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134 results on '"U.S. Department of Energy"'

1. Magnetic freeze-out and anomalous Hall effect in ZrTe5

Author: Adrien Gourgout, Maxime Leroux, Jean-Loup Smirr, Maxime Massoudzadegan, Ricardo P. S. M. Lobo, David Vignolles, Cyril Proust, Helmuth Berger, Qiang Li, Genda Gu, Christopher C. Homes, Ana Akrap, Benoît Fauqué, Laboratoire de Physique et d'Etude des Matériaux (UMR 8213) (LPEM), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire national des champs magnétiques intenses - Toulouse (LNCMI-T), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Jeunes Équipes de l'Institut de Physique du Collège de France (JEIPCdF), Collège de France (CdF (institution))-Centre National de la Recherche Scientifique (CNRS), Ecole Polytechnique Fédérale de Lausanne (EPFL), Department of Physics and Astronomy [Stony Brook], Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Brookhaven National Laboratory [Upton, NY] (BNL), UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE), Department of Physics [Fribourg], Université de Fribourg = University of Fribourg (UNIFR), ANR-19-CE30-0014,CP-Insulators,Localisation à N corps dans les isolants à paires de Cooper(2019), and ANR-18-CE92-0020,IFAS,Interaction entre ferroélctricité et la supraconductivité(2018)
Subjects: Condensed Matter - Materials Science, Condensed Matter - Strongly Correlated Electrons, Strongly Correlated Electrons (cond-mat.str-el), [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, Condensed Matter::Strongly Correlated Electrons, [PHYS.COND.CM-SCE]Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el], Condensed Matter Physics, Electronic, Optical and Magnetic Materials
Abstract: The ultra-quantum limit is achieved when a magnetic field confines an electron gas in its lowest spin-polarised Landau level. Here we show that in this limit, electron doped ZrTe$_5$ shows a metal-insulator transition followed by a sign change of the Hall and Seebeck effects at low temperature. We attribute this transition to a magnetic freeze-out of charge carriers on the ionised impurities. The reduction of the charge carrier density gives way to an anomalous Hall response of the spin-polarised electrons. This behaviour, at odds with the usual magnetic freeze-out scenario, occurs in this Dirac metal because of its tiny Fermi energy, extremely narrow band gap and a large $g$-factor. We discuss the different possible sources (intrinsic or extrinsic) for this anomalous Hall contribution., 14 pages, 4 figures
Published: 2022

2. Light-activated interlayer contraction in two-dimensional perovskites for high-efficiency solar cells

Author: Mercouri G. Kanatzidis, Boubacar Traore, Yafei Wang, Hao Zhang, Jean-Christophe Blancon, Joseph Strzalka, Justin M. Hoffman, Aditya D. Mohite, Wenbin Li, Joseph Essman, Claudine Katan, Ioannis Spanopoulos, Jared Crochet, Jacky Even, Austin Fehr, Jin Hou, Muhammad A. Alam, Siraj Sidhik, Reza Asadpour, Esther H. R. Tsai, Rice University [Houston], Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Institut des Fonctions Optiques pour les Technologies de l'informatiON (Institut FOTON), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Purdue University [West Lafayette], Northwestern University [Evanston], Los Alamos National Laboratory (LANL), Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Argonne National Laboratory [Lemont] (ANL), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-Centre National de la Recherche Scientifique (CNRS), UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE), NSF 20-587, National Science Foundation, N00014-20-1-2725, United States Department of Defense | United States Navy | ONR | Office of Naval Research Global, DE-SC0012704, U.S. Department of Energy, N00014-20-1-2725, United States Department of Defense | United States Navy | Office of Naval Research, and U.S. Department of Defense
Subjects: [PHYS]Physics [physics], Electron mobility, Materials science, Superlattice, Photovoltaic system, Biomedical Engineering, Bioengineering, 02 engineering and technology, Conductivity, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, 7. Clean energy, Atomic and Molecular Physics, and Optics, 0104 chemical sciences, X-ray photoelectron spectroscopy, Chemical physics, [CHIM]Chemical Sciences, General Materials Science, Electrical and Electronic Engineering, 0210 nano-technology, Dispersion (chemistry), Perovskite (structure), Voltage
Abstract: Understanding and tailoring the physical behaviour of halide perovskites under practical environments is critical for designing efficient and durable optoelectronic devices. Here, we report that continuous light illumination leads to >1% contraction in the out-of-plane direction in two-dimensional hybrid perovskites, which is reversible and strongly dependent on the specific superlattice packing. X-ray photoelectron spectroscopy measurements show that constant light illumination results in the accumulation of positive charges in the terminal iodine atoms, thereby enhancing the bonding character of inter-slab I–I interactions across the organic barrier and activating out-of-plane contraction. Correlated charge transport, structural and photovoltaic measurements confirm that the onset of the light-induced contraction is synchronized to a threefold increase in carrier mobility and conductivity, which is consistent with an increase in the electronic band dispersion predicted by first-principles calculations. Flux-dependent space-charge-limited current measurement reveals that light-induced interlayer contraction activates interlayer charge transport. The enhanced charge transport boosts the photovoltaic efficiency of two-dimensional perovskite solar cells up to 18.3% by increasing the device’s fill factor and open-circuit voltage. Light-induced contraction in the out-of-plane direction in two-dimensional (2D) hybrid perovskites enables the realization of high-efficiency 2D perovskite solar cells.
Published: 2021

3. Quasiparticle Band Structure and Phonon-Induced Band Gap Renormalization of the Lead-Free Halide Double Perovskite Cs2InAgCl6

Author: George Volonakis, Viet-Anh Ha, Hyungjun Lee, Feliciano Giustino, Marios Zacharias, University of Texas at Austin [Austin], Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Cyprus University of Technology, Robert A. Welch FoundationThe Welch Foundation [F-1990-20190330], Computational Materials Sciences Program - U.S. Department of Energy, Office of Science, Basic Energy Sciences United States Department of Energy (DOE) [DESC0020129], LRAC award [2007638], Office of Science of the U.S. Department of Energy United States Department of Energy (DOE) [DE-AC02-05CH11231], Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)
Subjects: Materials science, Band gap, Phonon, Halide, 02 engineering and technology, Perovskite, 01 natural sciences, Renormalization, Condensed Matter::Materials Science, Phonon-induced gap, 0103 physical sciences, Doping, [CHIM]Chemical Sciences, Physical and Theoretical Chemistry, 010306 general physics, Electronic band structure, Eigenvalues and eigenfunctions, Condensed matter physics, Materials Engineering, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Light emission properties, General Energy, Quasiparticle, Engineering and Technology, Double perovskite, Condensed Matter::Strongly Correlated Electrons, 0210 nano-technology
Abstract: International audience; The lead-free halide double perovskite Cs2InAgCl6 was recently designed in silico and subsequently synthesized in the lab. This perovskite is a wide-gap semiconductor with a direct band gap and exhibits extraordinary photoluminescence in the visible range upon Na doping. The light emission properties of Cs2InAgCl6 have successfully been exploited to fabricate stable single-emitter-based white-light LEDs with near unity quantum efficiency. An intriguing puzzle in the photophysics of this compound is that the onset of optical absorption is around 3 eV, but the luminescence peak is found around 2 eV. As a first step toward elucidating this mismatch and clarifying the atomic-scale mechanisms underpinning the observed luminescence, here, we report a detailed investigation of the quasiparticle band structure of Cs2InAgCl6 as well as the phonon-induced renormalization of the band structure. We perform calculations of bang gaps and effective masses using the GW method, and we calculate the phonon-induced band structure renormalization using the special displacement method. We find that GW calculations are rather sensitive to the functional used in the density functional theory calculations and that self-consistency on the eigenvalues is necessary to achieve quantitative agreement with experiments. Our most accurate band gap at room temperature is in the range of 3.1-3.2 eV and includes a phonon-induced gap renormalization of 0.2 eV. By computing the phonon-induced mass enhancement, we find that the electron carriers are in the weak polaronic coupling regime, while hole carriers are in the intermediate coupling regime as a result of the localized and directional nature of the Ag e(g) 4d states at the valence band top.
Published: 2021

4. Effect of Controlled Artificial Disorder on the Magnetic Properties of EuFe2(As1−xPx)2 Ferromagnetic Superconductor

Author: Tsuyoshi Tamegai, Kyuil Cho, Makariy A. Tanatar, Marcin Konczykowski, Daniele Torsello, Ivan Veshchunov, Gianluca Ghigo, Sunil Ghimire, Ruslan Prozorov, Ames Laboratory [Ames, USA], Iowa State University (ISU)-U.S. Department of Energy [Washington] (DOE), Laboratoire des Solides Irradiés (LSI), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Politecnico di Torino = Polytechnic of Turin (Polito), Moscow Institute of Physics and Technology [Moscow] (MIPT), Department of Applied Physics, The University of Tokyo, The University of Tokyo (UTokyo), Department of Applied Science and Technology [Politecnico di Torino] (DISAT), Istituto Nazionale di Fisica Nucleare, Sezione di Torino (INFN, Sezione di Torino), Istituto Nazionale di Fisica Nucleare (INFN), The Ames Laboratory (Ameslab), Iowa State University (ISU)-U.S. Department of Energy, Department of Physics and Astronomy [Ames, Iowa], Iowa State University (ISU), and the EMIR SIRIUS team
Subjects: Technology, Materials science, Proton, tunnel diode resonator (TDR), iron-based superconductors (IBS), FOS: Physical sciences, 02 engineering and technology, Electron, 01 natural sciences, Article, Superconductivity (cond-mat.supr-con), 0103 physical sciences, General Materials Science, Irradiation, 010306 general physics, tunnel diode resonator (TDR, Superconductivity, Microscopy, QC120-168.85, Coplanar waveguide resonator (CPWR), Iron-based superconductors (IBS), Tunnel diode resonator (TDR), Condensed matter physics, Condensed Matter - Superconductivity, QH201-278.5, Engineering (General). Civil engineering (General), 021001 nanoscience & nanotechnology, Ferromagnetic superconductor, TK1-9971, Magnetic field, [PHYS.COND.CM-S]Physics [physics]/Condensed Matter [cond-mat]/Superconductivity [cond-mat.supr-con], Descriptive and experimental mechanics, Ferromagnetism, coplanar waveguide resonator (CPWR), Diamagnetism, Electrical engineering. Electronics. Nuclear engineering, TA1-2040, 0210 nano-technology
Abstract: Static (DC) and dynamic (AC, at 14 MHz and 8 GHz) magnetic susceptibilities of single crystals of a ferromagnetic superconductor, EuFe2(As1−xPx)2 (x = 0.23), were measured in pristine state and after different doses of 2.5 MeV electron or 3.5 MeV proton irradiation. The superconducting transition temperature, Tc(H), shows an extraordinarily large decrease. It starts at Tc(H=0)≈24K in the pristine sample for both AC and DC measurements, but moves to almost half of that value after moderate irradiation dose. Remarkably, after the irradiation not only Tc moves significantly below the FM transition, its values differ drastically for measurements at different frequencies, ≈16 K in AC measurements and ≈12 K in a DC regime. We attribute such a large difference in Tc to the appearance of the spontaneous internal magnetic field below the FM transition, so that the superconductivity develops directly into the mixed spontaneous vortex-antivortex state where the onset of diamagnetism is known to be frequency-dependent. We also examined the response to the applied DC magnetic fields and studied the annealing of irradiated samples, which almost completely restores the superconducting transition. Overall, our results suggest that in EuFe2(As1−xPx)2 superconductivity is affected by local-moment ferromagnetism mostly via the spontaneous internal magnetic fields induced by the FM subsystem. Another mechanism is revealed upon irradiation where magnetic defects created in ordered Eu2+ lattice act as efficient pairbreakers leading to a significant Tc reduction upon irradiation compared to other 122 compounds. On the other hand, the exchange interactions seem to be weakly screened by the superconducting phase leading to a modest increase of Tm (less than 1 K) after the irradiation drives Tc to below Tm. Our results suggest that FM and SC phases coexist microscopically in the same volume.
Published: 2021
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5. Nature of native atomic defects in ZrTe$_5$ and their impact on the low-energy electronic structure

Author: G. D. Gu, Ana Akrap, B. Salzmann, B. Hildebrand, Aki Pulkkinen, Thomas Jaouen, Q. Li, Edoardo Martino, Shengnan Zhang, Oleg V. Yazyev, Claude Monney, Helmuth Berger, Université de Fribourg = University of Fribourg (UNIFR), Lappeenranta University of Technology (LUT), Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Ecole Polytechnique Fédérale de Lausanne (EPFL), Brookhaven National Laboratory [Upton, NY] (BNL), UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE), Institut de Physique des Nanostructures, P00P2_170544, Schweizerischer Nationalfonds zur F&#x00F6, rderung der Wissenschaftlichen Forschung, Osk. Huttusen säätiö, Brookhaven National Laboratory, DE-SC0012704, U.S. Department of Energy, University of Fribourg, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), and State University of New York (SUNY)-State University of New York (SUNY)
Subjects: Materials science, Physics and Astronomy (miscellaneous), phase-transition, FOS: Physical sciences, Electronic structure, wave, 01 natural sciences, 010305 fluids & plasmas, law.invention, Electrical resistivity and conductivity, law, Ionization, initio molecular-dynamics, 0103 physical sciences, General Materials Science, 010306 general physics, Spectroscopy, ComputingMilieux_MISCELLANEOUS, Condensed Matter - Materials Science, single-crystals, Condensed matter physics, Materials Science (cond-mat.mtrl-sci), 3. Good health, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Density of states, Density functional theory, Scanning tunneling microscope, Stoichiometry
Abstract: Over the past decades, investigations of the anomalous low-energy electronic properties of ZrTe$_5$ have reached a wide array of conclusions. An open question is the growth method's impact on the stoichiometry of ZrTe$_5$ samples, especially given the very small density of states near its chemical potential. Here we report on high resolution scanning tunneling microscopy and spectroscopy measurements performed on samples grown via different methods. Using density functional theory calculations, we identify the most prevalent types of atomic defects on the surface of ZrTe$_5$, namely Te vacancies and intercalated Zr atoms. Finally, we precisely quantify their density and outline their role as ionized defects in the anomalous resistivity of this material., Comment: 12 pages, 10 figures; Accepted for publication in Physical Review Materials
Published: 2020
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6. Concept of Lattice Mismatch and Emergence of Surface States in Two-dimensional Hybrid Perovskite Quantum Wells

Author: Sergei Tretiak, Boubacar Traore, Constantinos C. Stoumpos, Claudine Katan, Jacky Even, Jean-Christophe Blancon, Hsinhan Tsai, Laurent Pedesseau, Wanyi Nie, Mikael Kepenekian, Aditya D. Mohite, Mercouri G. Kanatzidis, Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Los Alamos National Laboratory (LANL), Institut des Fonctions Optiques pour les Technologies de l'informatiON (Institut FOTON), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Rice University [Houston], Northwestern University [Evanston], The work in France was supported by Agence Nationale pour la Recherche (TRANSHYPERO project) and was granted access to the HPC resources of [TGCC/CINES/IDRIS] under the allocation 2017-A0010907682 made by GENCI. The work at Los Alamos National Laboratory (LANL) was supported by LANL LDRD program (to J-C.B., W.N., S.T., and A.D.M.) and was partially performed at the Center for Nonlinear Studies. The work was conducted, in part, at the Center for Integrated Nanotechnologies (CINT), a U.S. Department of Energy, Office of Science user facility. Work at Northwestern University was supported by grant SC0012541 from the U.S. Department of Energy, Office of Science. C.C.S. and M.G.K. acknowledge the support under ONR Grant N00014-17-1-2231., Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Exciton, Bioengineering, 02 engineering and technology, Electronic structure, 010402 general chemistry, 01 natural sciences, Condensed Matter::Materials Science, General Materials Science, surface states, Quantum well, density functional theory, Perovskite (structure), Surface states, exciton, Condensed matter physics, business.industry, Mechanical Engineering, Heterojunction, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, lattice mismatch, Semiconductor, layered materials, Halide perovskites, Density functional theory, 0210 nano-technology, business
Abstract: International audience; Surface states are ubiquitous to semiconductors and significantly impact the physical properties and, consequently, the performance of optoelectronic devices. Moreover, surface effects are strongly amplified in lower dimensional systems such as quantum wells and nanostructures. Layered halide perovskites (LHPs) are two-dimensional solution-processed natural quantum wells where optoelectronic properties can be tuned by varying the perovskite layer thickness n, i.e., the number of octahedra spanning the layer. They are efficient semiconductors with technologically relevant stability. Here, a generic elastic model and electronic structure modeling are applied to LHPs heterostructures with various layer thickness. We show that the relaxation of the interface strain is triggered by perovskite layers above a critical thickness. This leads to the release of the mechanical energy arising from the lattice mismatch, which nucleates the surface reorganization and may potentially induce the formation of previously observed lower energy edge states. These states, which are absent in three-dimensional perovskites are anticipated to play a crucial role in the design of LHPs for optoelectronic systems.
Published: 2018

7. Antifogging abilities of model nanotextures

Author: Atikur Rahman, Stéphane Xavier, Thierry Midavaine, Antonio Checco, David Quéré, Charles T. Black, Timothée Mouterde, Christophe Clanet, Gaëlle Lehoucq, Laboratoire de Physique Statistique de l'ENS (LPS), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Thales Research and Technology [Palaiseau], THALES, Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Center for Functional Nanomaterials, State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), Laboratoire d'hydrodynamique (LadHyX), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Physique et mécanique des milieux hétérogenes (UMR 7636) (PMMH), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
Subjects: Materials science, Mechanical Engineering, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, Light reflectance, Nanotechnology, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Texture (geology), 0104 chemical sciences, law.invention, Broad spectrum, [SPI]Engineering Sciences [physics], Anti-reflective coating, Mechanics of Materials, law, General Materials Science, 0210 nano-technology, Scaling, ComputingMilieux_MISCELLANEOUS
Abstract: Nanometre-scale features with special shapes impart a broad spectrum of unique properties to the surface of insects. These properties are essential for the animal's survival, and include the low light reflectance of moth eyes, the oil repellency of springtail carapaces and the ultra-adhesive nature of palmtree bugs. Antireflective mosquito eyes and cicada wings are also known to exhibit some antifogging and self-cleaning properties. In all cases, the combination of small feature size and optimal shape provides exceptional surface properties. In this work, we investigate the underlying antifogging mechanism in model materials designed to mimic natural systems, and explain the importance of the texture's feature size and shape. While exposure to fog strongly compromises the water-repellency of hydrophobic structures, this failure can be minimized by scaling the texture down to nanosize. This undesired effect even becomes non-measurable if the hydrophobic surface consists of nanocones, which generate antifogging efficiency close to unity and water departure of droplets smaller than 2 μm.
Published: 2017

8. Extremely efficient internal exciton dissociation through edge states in layered 2D perovskites

Author: Costas C. Stoumpos, Pulickel M. Ajayan, Mikael Kepenekian, Claudine Katan, Hsinhan Tsai, Laurent Pedesseau, Sergei Tretiak, Chan Myae Myae Soe, Aditya D. Mohite, John Jared Crochet, Jacky Even, Jean-Christophe Blancon, Wanyi Nie, Mercouri G. Kanatzidis, Matthew Y. Sfeir, Kannatassen Appavoo, Los Alamos National Laboratory (LANL), Northwestern University [Evanston], Rice University [Houston], Institut des Fonctions Optiques pour les Technologies de l'informatiON (Institut FOTON), École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), The work in France was supported by Cellule Energie du CNRS (SOLHYBTRANS Project) and University of Rennes 1 (Action Incitative, Défis Scientifique Emergents 2015)., CINT/LANL contract DE-AC52-06NA25396, SOLHYBTRANS, Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), and State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)
Subjects: [PHYS]Physics [physics], Multidisciplinary, Condensed matter physics, Chemistry, Band gap, Exciton, 02 engineering and technology, Electronic structure, Electron, 010402 general chemistry, 021001 nanoscience & nanotechnology, 7. Clean energy, 01 natural sciences, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Condensed Matter::Materials Science, [SPI]Engineering Sciences [physics], [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Coulomb, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Thin film, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology, Quantum well, Perovskite (structure)
Abstract: How perovskites have the edge Two-dimensional Ruddlesden-Popper perovskites form quantum wells by sandwiching inorganic-organic perovskite layers used in photovoltaic devices between organic layers. Blancon et al. show that if the perovskite layer is more than two unit cells thick, photogenerated excitons undergo an unusual but highly efficient process for creating free carriers that can be harvested in photovoltaic devices (see the Perspective by Bakr and Mohammed). Lower-energy local states at the edges of the perovskite layer facilitate dissociation into electrons and holes that are well protected from recombination. Science , this issue p. 1288 ; see also p. 1260
Published: 2017

9. Crystal electric field excitations in the quasicrystal approximant TbCd 6 studied by inelastic neutron scattering

Author: Pinaki Das, M. de Boissieu, Alan I. Goldman, Takanobu Hiroto, Paul C. Canfield, Sergey L. Bud'ko, Rebecca Flint, Tai Kong, P.-F. Lory, Andreas Kreyssig, Science et Ingénierie des Matériaux et Procédés (SIMaP ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Tokyo University Sci. Dept. Sci. & Technol., The University of Tokyo (UTokyo), The Ames Laboratory (Ameslab), Iowa State University (ISU)-U.S. Department of Energy, Ames Laboratory [Ames, USA], and Iowa State University (ISU)-U.S. Department of Energy [Washington] (DOE)
Subjects: Physics, Quasielastic scattering, Condensed matter physics, Inverse, 02 engineering and technology, Neutron scattering, Inelastic scattering, 021001 nanoscience & nanotechnology, 01 natural sciences, Inelastic neutron scattering, Paramagnetism, Magnetization, 0103 physical sciences, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 010306 general physics, 0210 nano-technology, Intensity (heat transfer), ComputingMilieux_MISCELLANEOUS
Abstract: We have performed inelastic neutron scattering measurements on powder samples of the quasicrystal approximant, ${\mathrm{TbCd}}_{6}$, grown using isotopically enriched $^{112}\mathrm{Cd}$. Both quasielastic scattering and distinct inelastic excitations were observed below 3 meV. The intensity of the quasielastic scattering measured in the paramagnetic phase diverges as ${T}_{\mathrm{N}}\ensuremath{\sim}22$ K is approached from above. The inelastic excitations, and their evolution with temperature, are well characterized by the leading term, ${B}_{2}^{0}{O}_{2}^{0}$, of the crystal electric field (CEF) level scheme for local pentagonal symmetry for the rare-earth ions [S. Jazbec et al., Phys. Rev. B 93, 054208 (2016)] indicating that the Tb moment is directed primarily along the unique local pseudofivefold axis of the Tsai-type clusters. We also find good agreement between the inverse susceptibility determined from magnetization measurements using a magnetically diluted ${\mathrm{Tb}}_{0.05}{\mathrm{Y}}_{0.95}{\mathrm{Cd}}_{6}$ sample and that calculated using the CEF level scheme determined from the neutron measurements.
Published: 2017

10. Orbital breathing effects in the computation of x-ray d-ion spectra in solids by ab initio wave-function-based methods

Author: Hermann Stoll, Claude Monney, Jochen Geck, Alexander O. Mitrushchenkov, Nikolay A. Bogdanov, Roberto Kraus, Thorsten Schmitt, Liviu Hozoi, Valentina Bisogni, Jeroen van den Brink, Ke-Jin Zhou, Max Planck Institute for Solid State Research, Max-Planck-Gesellschaft, Leibniz Institute for Solid State and Materials Research (IFW Dresden), Leibniz Association, Brookhaven National Laboratory Mational Synchrotron Light Source (BNL NSLS), Brookhaven National Laboratory, The Swiss Light Source (SLS) (SLS-PSI), Paul Scherrer Institute (PSI), Physikalisch-Chemisches Institut [Zürich], Universität Zürich [Zürich] (UZH), STFC, ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, STFC, ISIS Facility, University of Salzburg, Laboratoire de Modélisation et Simulation Multi Echelle (MSME), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université Paris-Est Marne-la-Vallée (UPEM), Universität Stuttgart [Stuttgart], Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Universität Zürich [Zürich] = University of Zurich (UZH), ISIS Neutron and Muon Source (ISIS), STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC)-Science and Technology Facilities Council (STFC), Université Paris-Est Marne-la-Vallée (UPEM)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), and State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)
Subjects: ab initio computational methods, Ab initio, FOS: Physical sciences, 02 engineering and technology, core-hole potential, 01 natural sciences, Molecular physics, Spectral line, Ion, Condensed Matter - Strongly Correlated Electrons, 0103 physical sciences, General Materials Science, Cuprate, 010306 general physics, Wave function, resonant inelastic x-ray scattering (RIXS), Physics, Strongly Correlated Electrons (cond-mat.str-el), Scattering, transition-metal oxides, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Polarization (waves), [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Relaxation (physics), 0210 nano-technology
Abstract: International audience; In existing theoretical approaches to core-level excitations of transition-metal ions in solids relaxation and polarization effects due to the inner core hole are often ignored or described phenomenologically. Here we set up an ab initio computational scheme that explicitly accounts for such physics in the calculation of x-ray absorption and resonant inelastic x-ray scattering spectra. Good agreement is found with experimental transition-metal L-edge data for the strongly correlated d9 cuprate Li2CuO2, for which we determine the absolute scattering intensities. The newly developed methodology opens the way for the investigation of even more complex dn electronic structures of group VI B to VIII B correlated oxide compounds.
Published: 2017

11. Polaron stabilization by cooperative lattice distortion and cation rotations in hybrid perovskite materials

Author: Hsinhan Tsai, Amanda Neukirch, Laurent Pedesseau, Sergei Tretiak, Wanyi Nie, Jacky Even, Matthew Y. Sfeir, Gautam Gupta, Jean-Christophe Blancon, Aditya D. Mohite, Kannatassen Appavoo, Jared Crochet, Claudine Katan, Los Alamos National Laboratory (LANL), Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Fonctions Optiques pour les Technologies de l'informatiON (FOTON), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Université européenne de Bretagne - European University of Brittany (UEB)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-Télécom Bretagne-Centre National de la Recherche Scientifique (CNRS), The work in France was supported by Cellule Energie du CNRS (SOLHYBTRANS Project) and University of Rennes 1 (Action Incitative, Défis Scientifique Emergents 2015). J.E. work was supported by the Fondation d’entreprises banque Populaire de l’Ouest under Grant PEROPHOT 2015.The work at Los Alamos National Laboratory (LANL) was supported by the LANL LDRD program (A.J.N., A.D.M, G.G., and S.T.). This work was done in part at Center for Nonlinear Studies (CNLS) and the Center for Integrated Nano- technologies CINT), a U.S. Department of Energy and Office of Basic Energy Sciences user facility, at LANL. This research used resources provided by the LANL Institutional Computing Program. LANL is operated by Los Alamos National Security, LLC, for the National Nuclear Security Administration of the U.S. Department of Energy under contract DE-AC52- 06NA25396.This research used resources of the Center for Functional Nanomaterials, which is a US DOE Office of Science Facility, at Brookhaven National Laboratory under Contract No. DE- SC0012704., Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR)-Université européenne de Bretagne - European University of Brittany (UEB)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-Télécom Bretagne-Centre National de la Recherche Scientifique (CNRS), and even, jacky
Subjects: Materials science, [SPI] Engineering Sciences [physics], Inorganic chemistry, Ionic bonding, Bioengineering, 02 engineering and technology, Electronic structure, 010402 general chemistry, Polaron, 7. Clean energy, 01 natural sciences, [PHYS] Physics [physics], photovoltaic, [SPI]Engineering Sciences [physics], [CHIM] Chemical Sciences, [CHIM]Chemical Sciences, General Materials Science, ComputingMilieux_MISCELLANEOUS, Perovskite (structure), Photocurrent, [PHYS]Physics [physics], polaron, Mechanical Engineering, Charge density, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, cation rotations, Chemical physics, Organic−inorganic perovskite, Density functional theory, Charge carrier, 0210 nano-technology
Abstract: International audience; Solution-processed organometallic perovskites have rapidly developed into a top candidate for the active layer of photovoltaic devices. Despite the remarkable progress associated with perovskite materials, many questions about the fundamental photophysical processes taking place in these devices remain open. High on the list of unexplained phenomena are very modest mobilities despite low charge carrier effective masses. Moreover, experiments elucidate unique degradation of photocurrent affecting stable operation of perovskite solar cells. These puzzles suggest that while ionic hybrid perovskite devices may have efficiencies on par with conventional Si and GaAs devices, they exhibit more complicated charge transport phenomena. Here we report the results from an in-depth computational study of small polaron formation, electronic structure, charge density, and reorganization energies using both periodic boundary conditions and isolated structures. Using the hybrid Density Functional Theory, we found that volumetric strain in a CsPbI3 cluster creates a polaron with binding energy of around 300 meV and 900 meV for holes and electrons, respectively. In the MAPbI3 (MA=CH3NH3) cluster, both volumetric strain and MA reorientation effects lead to larger binding energies at around 600 meV and 1300 meV for holes and electrons, respectively. Such large reorganization energies suggest appearance of small polarons in organometallic perovskite materials. The fact that both volumetric lattice strain and MA molecular rotational degrees of freedom can cooperate to create and stabilize polarons, indicates that in order to mitigate this problem, formamidinium (FA=HC(NH2)2) and cesium (Cs) based crystals and alloys, are potentially better materials for solar cell and other optoelectronic applications.
Published: 2016

12. Surface-induced spin state locking of the [Fe(H2B(pz)2)2(bipy)] spin crossover complex

Author: Peter A. Dowben, Ahmad Naim, Jing Liu, Xin Zhang, Jean-François Létard, Patrick Rosa, Guillaume Chastanet, Axel Enders, George E. Sterbinsky, Dario Arena, Sai Mu, Sumit Beniwal, Department of Physics and Astronomy [Lincoln], University of Nebraska [Lincoln], University of Nebraska System-University of Nebraska System, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université de Bordeaux (UB), Department of Chemical Engineering, Northeastern University [Boston], Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), he National Science Foundation through the Nebraska MRSEC (DMR-1420645), the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. DE-AC02-98CH10886., and ANR-11-BS08-0006,MultiSelf,Éléments de mémoires multifonctionnels utilisant des connections supramoléculaires auto assemblées(2011)
Subjects: Spin states, Spin transition, molecular magnetism, 02 engineering and technology, Electronic structure, 010402 general chemistry, 01 natural sciences, law.invention, Spin crossover, law, Molecule, General Materials Science, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Fe(II) spin-crossover, Spectroscopy, Condensed matter physics, Chemistry, Bilayer, PACS: 75.30.Wx, 68.37Ef, 68.43Fg, 79.60.Dp, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, spin-crossover, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Condensed Matter::Strongly Correlated Electrons, Scanning tunneling microscope, spin state locking, 0210 nano-technology
Abstract: International audience; Temperature- and coverage-dependent studies of the Au(1 1 1)-supported spin crossover Fe(II) complex (SCO) of the type [Fe(H2B(pz)2)2(bipy)] with a suite of surface-sensitive spectroscopy and microscopy tools show that the substrate inhibits thermally induced transitions of the molecular spin state, so that both high-spin and low-spin states are preserved far beyond the spin transition temperature of free molecules. Scanning tunneling microscopy confirms that [Fe(H2B(pz)2)2(bipy)] grows as ordered, molecular bilayer islands at sub-monolayer coverage and as disordered film at higher coverage. The temperature dependence of the electronic structure suggest that the SCO films exhibit a mixture of spin states at room temperature, but upon cooling below the spin crossover transition the film spin state is best described as a mix of high-spin and low-spin state molecules of a ratio that is constant. This locking of the spin state is most likely the result of a substrate-induced conformational change of the interfacial molecules, but it is estimated that also the intra-atomic electron–electron Coulomb correlation energy, or Hubbard correlation energy U, could be an additional contributing factor.
Published: 2016

13. Inelastic X-ray scattering investigations of lattice dynamics in SmFeAsO1−F superconductors

Author: Mathieu Le Tacon, J. Noffsinger, P. Toulemonde, J. Karpinski, John Hill, T. R. Forrest, A. Palenzona, Ch. Rüegg, A. C. Walters, Michael Krisch, Nikolai D. Zhigadlo, Alexei Bosak, D. F. McMorrow, Max-Planck-Institut für Festkörperforschung, Max-Planck-Gesellschaft, London Centre for Nanotechnology and Department of Physics and Astronomy, University College of London [London] (UCL), Department of Physics [Berkeley], University of California [Berkeley], University of California-University of California, London Centre for Nanotechnology, European Synchrotron Radiation Facility (ESRF), Matériaux, Rayonnements, Structure (MRS), Institut Néel (NEEL), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), NR-INFM-LAMIA, Universita degli studi di Genova, Laboratory for Solid State Physics [ETH Zürich], Department of Physics [ETH Zürich] (D-PHYS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Department of Physics [Upton], Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), and State University of New York (SUNY)-State University of New York (SUNY)
Subjects: Angular momentum, Phonon, FOS: Physical sciences, 02 engineering and technology, 01 natural sciences, Superconductivity (cond-mat.supr-con), Renormalization, Condensed Matter::Materials Science, Condensed Matter - Strongly Correlated Electrons, Condensed Matter::Superconductivity, 0103 physical sciences, Dispersion (optics), General Materials Science, 010306 general physics, Spin (physics), Superconductivity, Physics, Strongly Correlated Electrons (cond-mat.str-el), Condensed matter physics, Scattering, Condensed Matter - Superconductivity, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Coupling (probability), 3. Good health, [PHYS.COND.CM-S]Physics [physics]/Condensed Matter [cond-mat]/Superconductivity [cond-mat.supr-con], Condensed Matter::Strongly Correlated Electrons, 0210 nano-technology
Abstract: We report measurements of the phonon density of states as measured with inelastic x-ray scattering in SmFeAsO$_{1-x}$F$_y$ powders. An unexpected strong renormalization of phonon branches around 23 meV is observed as fluorine is substituted for oxygen. Phonon dispersion measurements on SmFeAsO$_{1-x}$F$_y$ single crystals allow us to identify the 21 meV A$_{1g}$ in-phase (Sm,As) and the 26 meV B$_{1g}$ (Fe,O) modes to be responsible for this renormalization, and may reveal unusual electron-phonon coupling through the spin channel in iron-based superconductors., 4 pages, 3 figures, submitted for SNS2010 conference proceedings
Published: 2011

14. Spin density wave dislocation in chromium probed by coherent X-ray diffraction

Author: V. L.R. Jacques, D. Le Bolloc’h, S. Ravy, C. Giles, F. Livet, S. B. Wilkins, Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des Solides (LPS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11), Inst Fis Glob Wataghin, Univ. Estadual Campinas, Science et Ingénierie des Matériaux et Procédés (SIMaP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Chimie du CNRS (INC)-Institut National Polytechnique de Grenoble (INPG), Brookhaven, Natl Lab., Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National Polytechnique de Grenoble (INPG)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Diffraction, Materials science, conduction noise, FOS: Physical sciences, chemistry.chemical_element, 02 engineering and technology, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Condensed Matter - Strongly Correlated Electrons, Chromium, strain, charge, alloys, generation, harmonics, 0103 physical sciences, Spin density wave, patterns, 010306 general physics, Condensed Matter - Materials Science, Strongly Correlated Electrons (cond-mat.str-el), Condensed matter physics, Magnetic order, scattering, Materials Science (cond-mat.mtrl-sci), transition, dynamics, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, Reflection (mathematics), chemistry, X-ray crystallography, Dislocation, 0210 nano-technology
Abstract: We report on the study of a magnetic dislocation in pure chromium. Coherent x-ray diffraction profiles obtained on the incommensurate Spin Density Wave (SDW) reflection are consistent with the presence of a dislocation of the magnetic order, embedded at a few micrometers from the surface of the sample. Beyond the specific case of magnetic dislocations in chromium, this work may open up a new method for the study of magnetic defects embedded in the bulk., Comment: 8 pages, 7 figures
Published: 2009

15. Signature of a polyamorphic transition in the THz spectrum of vitreous GeO2

Author: Filippo Bencivenga, Ho-kwang Mao, Roberto Verbeni, Shibing Wang, Daniele Antonangeli, Yong Q. Cai, C. N. Kodituwakku, Alfred Q. R. Baron, Satoshi Tsutsui, Yan Li, Andrea Battistoni, Alessandro Cunsolo, Dima Bolmatov, National Synchrotron Light Source II, Brookhaven National Laboratory [Upton, NY] (BNL), UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE), American Physical Society, Research Road, Ridge, Department of Geological Sciences [Stanford] (GS), Stanford EARTH, Stanford University-Stanford University, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Sincrotrone Trieste, Strada Statale 14 km 163.5, Area Science Park, I-34012 Trieste, Italy, Dipartimento di Fisica, Università degli studi di Trieste = University of Trieste, European Synchrotron Radiation Facility (ESRF), Japan Synchrotron Radiation Research Institute [Hyogo] (JASRI), RIKEN SPring-8 Center [Hyogo] (RIKEN RSC), RIKEN - Institute of Physical and Chemical Research [Japon] (RIKEN), Geophysical Laboratory [Carnegie Institution], Carnegie Institution for Science, Center for High Pressure Science & Technology Advanced Research, Center for High Pressure Science & Technology Advanced Research (HPSTAR), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Università degli studi di Trieste, and Carnegie Institution for Science [Washington]
Subjects: Spectral shape analysis, Materials science, Phonon, Terahertz radiation, FOS: Physical sciences, 02 engineering and technology, 01 natural sciences, Article, Condensed Matter::Materials Science, Physics - Chemical Physics, 0103 physical sciences, Dispersion (optics), 010306 general physics, Condensed Matter - Statistical Mechanics, Chemical Physics (physics.chem-ph), Range (particle radiation), Condensed Matter - Materials Science, Multidisciplinary, Condensed matter physics, Statistical Mechanics (cond-mat.stat-mech), Scattering, Materials Science (cond-mat.mtrl-sci), Disordered Systems and Neural Networks (cond-mat.dis-nn), Condensed Matter - Disordered Systems and Neural Networks, 021001 nanoscience & nanotechnology, Rutile, [SDU]Sciences of the Universe [physics], 0210 nano-technology, Ambient pressure
Abstract: The THz spectrum of density fluctuations, $S(Q, \omega)$, of vitreous GeO$_2$ at ambient temperature was measured by inelastic x-ray scattering from ambient pressure up to pressures well beyond that of the known $\alpha$-quartz to rutile polyamorphic (PA) transition. We observe significant differences in the spectral shape measured below and above the PA transition, in particular, in the 30-80 meV range. Guided by first-principle lattice dynamics calculations, we interpret the changes in the phonon dispersion as the evolution from a quartz-like to a rutile-like coordination. Notably, such a crossover is accompanied by a cusp-like behavior in the pressure dependence of the elastic response of the system. Overall, the presented results highlight the complex fingerprint of PA phenomena on the high-frequency phonon dispersion., Comment: 18 pages, 5 figures
Published: 2015
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16. Discovery of Liquid Crystal Mesophases with a Six-Layer Periodicity

Author: Ron Pindak, Shun Wang, P. Barois, LiDong Pan, Cheng-Cher Huang, School of Physics and Astronomy, University of Minnesota [Minneapolis], Key Laboratory of Artificial Structures and Quantum Control, Shanghai Jiao Tong University [Shanghai], Department of Physics and Astronomy [Baltimore], Johns Hopkins University ( JHU ), Centre de recherches Paul Pascal ( CRPP ), Centre National de la Recherche Scientifique ( CNRS ), Photon Sciences Directorate, Brookhaven National Laboratory, School of Physics and Astronomy [Minneapolis], University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, Johns Hopkins University (JHU), Centre de recherches Paul Pascal (CRPP), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), and State University of New York (SUNY)-State University of New York (SUNY)
Subjects: Diffraction, Materials science, Birefringence, Mesophase, General Chemistry, Dielectric, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas, SmCd6 * phase, SmC* variant phases, Crystallography, [ CHIM.CRIS ] Chemical Sciences/Cristallography, Liquid crystal, Ellipsometry, Phase (matter), 0103 physical sciences, resonant x-ray diffraction, [CHIM.CRIS]Chemical Sciences/Cristallography, null transmission ellipsometry, General Materials Science, 010306 general physics, Ternary operation
Abstract: International audience; In 2006, employing ellipsometry and resonant x-ray diffraction, our research group discovered a liquid crystal mesophase having a six-layer periodicity in a ternary mixture (mixture A) as well as in a binary mixture (mixture B). This phase showsantiferroelectric-like properties. Subsequently, J. K. Vij’s group used field-induced birefringence to explore the physical properties of various binary mixtures similar to mixture B. Recently, Y. Takanishi et al. obtained dielectric responses and twodimensional microbeam resonant x-ray diffraction profiles as a function of temperature from a different binary mixture with one compound of the mixture containing a central bromine atom. They discovered another new mesophase which shows a six-layer structure and displays ferrielectric-like responses along with a different phase sequence. This article will review the sequence of events leading up to the discovery of the new phases with a six-layer periodicity and highlight differences in conclusions about the new phases and an ongoing debate about the existence of a phase with five-layer periodicity.
Published: 2015

17. Liquid crystal mesophases beyond commensurate four-layer periodicity

Author: Ron Pindak, Yuji Sasaki, Kenji Ema, Shun Wang, P. Barois, B. K. McCoy, Z. Q. Liu, Cheng-Cher Huang, LiDong Pan, School of Physics and Astronomy [Minneapolis], University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, Key Laboratory of Artificial Structures and Quantum Control, Shanghai Jiao Tong University [Shanghai], Department of Physics and Astronomy [Baltimore], Johns Hopkins University (JHU), Department of Mathematics, Physics, and Staitistics [Azusa], Azusa Pacific University, Department of Applied Physics, Graduate School of Engineering, The University of Tokyo, Centre de recherches Paul Pascal (CRPP), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Photon Sciences Directorate, Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Contract N° DE-AC02-98CH10886, School of Physics and Astronomy, University of Minnesota [Minneapolis], Johns Hopkins University ( JHU ), Department of Physics and Astronomy, St. Cloud State University, Department of Mathematics and Physics, Azusa Pacific University, Centre de recherches Paul Pascal ( CRPP ), Centre National de la Recherche Scientifique ( CNRS ), and Brookhaven National Laboratory
Subjects: Diffraction, Materials science, Theoretical models, 02 engineering and technology, 01 natural sciences, resonant X-ray diffraction, SmC∗, SmC∗d6, [ CHIM.CRIS ] Chemical Sciences/Cristallography, null-transmission ellipsometry, Liquid crystal, Ellipsometry, Phase (matter), Physical phenomena, 0103 physical sciences, [CHIM.CRIS]Chemical Sciences/Cristallography, General Materials Science, 010306 general physics, Mesophase, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, variant phases, Crystallography, Chemical physics, 0210 nano-technology, Ternary operation
Abstract: International audience; For more than one decade, SmC∗d4, SmC∗d3, andSmC∗ A were the only three confirmed commensurate SmC* variant phases with periodicities less than or equal four layers. In 2006, employing ellipsometry and resonant X-ray diffraction (RXRD), our research team first discovered a new liquid crystal mesophase having a six-layer periodicity in one ternary mixture which includes one sulfur-containing compound. From our ellipsometric results, this phase showed antiferroelectric-like optical response. This novel discovery inspired renewed interest to search for liquid crystal mesophases with commensurateperiodicities greater than four layers. Soon after, another mesophase having a six-layer structure and showing a ferrielectric-like dielectric response, instead, was uncovered by RXRD measurements on a different binary mixture which has one bromine-containing compound. Meanwhile mesophases having a 5-, 8-, 12- or 15-layer periodicity were reported. However, numerous questions remain to be addressed associated with these unusual reported phases. Theoretical models giving rise to mesophases with periodicities greater than four layers have been developed; but, to date, none of them haveprovided satisfactory explanations of all the physical phenomena related to the mesophases exhibiting a six-layer structure. Moreover, the question “what is the source of long-range interactions between liquid-like smectic layers, which are responsible for establishing mesophases with long periodicities and mean-field behavior of the smectic-A–smectic-C transition?” remains unanswered for more than three decades.
Published: 2015

18. Antiferromagnetic phase of the gapless semiconductorV3Al

Author: Michelle E. Jamer, Don Heiman, Andrés Saúl, Badih A. Assaf, George E. Sterbinsky, Laura H. Lewis, Dario Arena, Guillaume Radtke, Department of Physics [UMass, Boston], University of Massachusetts [Boston] (UMass Boston), University of Massachusetts System (UMASS)-University of Massachusetts System (UMASS), Photon Sciences Directorate, Brookhaven National Laboratory [Upton, NY] (BNL), UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE), Department of Chemical Engineering, Northeastern University [Boston], Department of Civil and Environmental Engineering [Cambridge] (CEE), Massachusetts Institute of Technology (MIT), Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), and State University of New York (SUNY)-State University of New York (SUNY)
Subjects: Materials science, FOS: Physical sciences, 02 engineering and technology, 01 natural sciences, Condensed Matter::Materials Science, Magnetization, Gapless playback, PACS : 75.50.Pp, 71.15.Mb, 75.25.−j, 75.50.Ee, 0103 physical sciences, Antiferromagnetism, 010306 general physics, [PHYS]Physics [physics], Condensed Matter::Quantum Gases, Condensed Matter - Materials Science, Magnetic moment, Condensed matter physics, Spintronics, Materials Science (cond-mat.mtrl-sci), Magnetic semiconductor, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, Magnetic field, Condensed Matter::Strongly Correlated Electrons, Density functional theory, 0210 nano-technology
Abstract: Discovering new antiferromagnetic compounds is at the forefront of developing future spintronic devices without fringing magnetic fields. The antiferromagnetic gapless semiconducting D03 phase of V3Al was successfully synthesized via arc-melting and annealing. The antiferromagnetic properties were established through synchrotron measurements of the atom-specific magnetic moments, where the magnetic dichroism reveals large and oppositely-oriented moments on individual V atoms. Density functional theory calculations confirmed the stability of a type G antiferromagnetism involving only two-third of the V atoms, while the remaining V atoms are nonmagnetic. Magnetization, x-ray diffraction and transport measurements also support the antiferromagnetism. This archetypal gapless semiconductor may be considered as a cornerstone for future spintronic devices containing antiferromagnetic elements., Comment: Accepted to Physics Review B on 02/23/15
Published: 2015

19. Low-voltage organic electronics based on a gate-tunable injection barrier in vertical graphene-organic semiconductor heterostructures

Author: James Hone, Robert A. Barton, Ioannis Kymissis, Chang-Hyun Kim, Htay Hlaing, Fabio Carta, Nicholas Petrone, Chang-Yong Nam, Department of Electrical Engineering, Columbia University [New York], Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Center for Functional Nanomaterials, Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), and Department of Mechanical Engineering
Subjects: Materials science, Bioengineering, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, 7. Clean energy, law.invention, [SPI.MAT]Engineering Sciences [physics]/Materials, law, Lab-On-A-Chip Devices, Hardware_INTEGRATEDCIRCUITS, General Materials Science, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, Electrodes, Organic electronics, business.industry, Graphene, Mechanical Engineering, Transistor, Heterojunction, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, [SPI.TRON]Engineering Sciences [physics]/Electronics, Organic semiconductor, Semiconductor, Semiconductors, Thin-film transistor, Optoelectronics, Graphite, 0210 nano-technology, business, Low voltage
Abstract: International audience; The vertical integration of graphene with inorganic semiconductors, oxide semiconductors, and newly emerging layered materials has recently been demonstrated as a promising route toward novel electronic and optoelectronic devices. Here, we report organic thin film transistors based on vertical heterojunctions of graphene and organic semiconductors. In these thin heterostructure devices, current modulation is accomplished by tuning of the injection barriers at the semiconductor/graphene interface with the application of a gate voltage. N-channel devices fabricated with a thin layer of C60 show a room temperature on/off ratio >104 and current density of up to 44 mAcm–2. Because of the ultrashort channel intrinsic to the vertical structure, the device is fully operational at a driving voltage of 200 mV. A complementary p-channel device is also investigated, and a logic inverter based on two complementary transistors is demonstrated. The vertical integration of graphene with organic semiconductors via simple, scalable, and low-temperature fabrication processes opens up new opportunities to realize flexible, transparent organic electronic, and optoelectronic devices.
Published: 2015

20. Three energy scales in the superconducting state of hole-doped cuprates detected by electronic Raman scattering

Author: Alain Sacuto, G. D. Gu, Yann Gallais, Ruidan Zhong, Maximilien Cazayous, Dorothée Colson, M. A. Measson, A. Forget, John Schneeloch, S. Benhabib, Laboratoire Matériaux et Phénomènes Quantiques (MPQ (UMR_7162)), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Condensed Matter Physics and Materials Sciences Department, Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Laboratoire Nano-Magnétisme et Oxydes (LNO), Service de physique de l'état condensé (SPEC - UMR3680), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Brookhaven National Laboratory, UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), and State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)
Subjects: Superconductivity, Physics, [PHYS]Physics [physics], Condensed matter physics, Condensed Matter - Superconductivity, Doping, FOS: Physical sciences, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Electronic, Optical and Magnetic Materials, Superconductivity (cond-mat.supr-con), symbols.namesake, Condensed Matter::Superconductivity, 0103 physical sciences, Homogeneous space, symbols, Cuprate, Condensed Matter::Strongly Correlated Electrons, 010306 general physics, 0210 nano-technology, Merge (version control), Raman scattering
Abstract: We explored by electronic Raman scattering the superconducting state of Bi-2212 single crystal by performing a fine tuned doping study. We found three distinct energy scales in A1g, B1g and B2g symmetries which show three distinct doping dependencies. Above p=0.22 the three energies merge, below p=0.12, the A1g scale is no more detectable while the B1g and B2g scales become constant in energy. In between, the A1g and B1g scales increase monotonically with under-doping while the B2g one exhibits a maximum at p=0.16. The three superconducting energy scales appear to be an universal feature of hole-doped cuprates. We propose that the non trivial doping dependence of the three scales originates from Fermi surface topology changes and reveals competing orders inside the superconducting dome., Comment: 6 pages, 5 figures
Published: 2015

21. Towards delafossite structure of Cu-Cr-O thin films deposited by reactive magnetron sputtering: Influence of substrate temperature on optoelectronics properties

Author: Alain Billard, Mohammad Arab Pour Yazdi, Jean-François Pierson, Pascal Briois, Hui Sun, Frédéric Sanchette, US Department of Energy Joint Genome Institute, U.S Department of Energy, U.S. Department of Energy [Washington] (DOE)-U.S. Department of Energy [Washington] (DOE), Laboratoire d'Études et de Recherches sur les Matériaux, les Procédés et les Surfaces (IRTES - LERMPS), Université de Technologie de Belfort-Montbeliard (UTBM)-Institut de Recherche sur les Transports, l'Energie et la Société - IRTES, Laboratoire Commun de Belfort : Hydrogène et Pile à Combustible pour les applications au transport (FC LAB), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Belfort-Montbeliard (UTBM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Laboratoire des Technologies Nouvelles (IFSTTAR/COSYS/LTN), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Laboratoire Transports et Environnement (IFSTTAR/AME/LTE), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université de Lyon-Université de Lyon, Institut Jean Lamour (IJL), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Systèmes Mécaniques et d'Ingénierie Simultanée (LASMIS), Institut Charles Delaunay (ICD), Université de Technologie de Troyes (UTT)-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Troyes (UTT)-Centre National de la Recherche Scientifique (CNRS), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Laboratoire Transports et Environnement (IFSTTAR/AME/LTE), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université de Lyon-Université de Lyon-Laboratoire des Technologies Nouvelles (IFSTTAR/COSYS/LTN), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Technologie de Belfort-Montbeliard (UTBM)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), and Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)
Subjects: 010302 applied physics, Materials science, Annealing (metallurgy), business.industry, 02 engineering and technology, [CHIM.MATE]Chemical Sciences/Material chemistry, engineering.material, Conductivity, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Surfaces, Coatings and Films, Amorphous solid, Delafossite, Sputtering, 0103 physical sciences, engineering, Transmittance, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Figure of merit, Optoelectronics, Thin film, 0210 nano-technology, business, Instrumentation
Abstract: International audience; Cu-Cr-O thin films were co-sputtered from metallic Cu and Cr targets in the presence of a reactive argon-oxygen gas mixture. Evolution of the coatings composition as a function of the discharge current dissipated on each target allowed to obtain convenient composition. The films deposited at ambient temperature (without intentional heating of substrate) were initially amorphous and need to be annealed at different temperature under vacuum to achieve delafossite structure. In this case, the delafossite structure presented a thermal instability to the annealing temperature. CuCr2O4 and CuO as the secondary phases were clearly detected by XRD analysis, and could evidently affect the CuCrO2 films optoelectronic properties. Cu-Cr-O thin films were also deposited at high temperatures (substrate temperature varied from 923 to 1083 K) to investigate the influence of substrate temperature on the structure, morphology and optoelectronic properties of the films. Relatively, raising the substrate temperature up to 1033 K was better to obtain CuCrO2 delafossite phase and improved their optoelectronic properties. The optimum conductivity and transparency were achieved for the film deposited at about 1033 K with figure of merit of 6.18 x 10(-13) Omega(-1) (sigma approximate to 1.34 x 10(-2) S cm(-1) and the maximum visible transmittance up to 43%).
Published: 2015

22. Self-Organization of Quantum Rods Induced by Lipid Membrane Corrugations

Author: Kevin G. Yager, Jean-Claude Ameline, Valérie Marchi, Thomas Bizien, Franck Artzner, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Center for Functionnal Nanomaterials, Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Brookhaven National Laboratory, Office of Science, European Regional Development Fund, Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), and State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)
Subjects: Nanostructure, Materials science, Membrane lipids, education, Nanoparticle, Nanotechnology, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Fluorescence, Membrane Lipids, X-Ray Diffraction, Liquid crystal, Scattering, Small Angle, Electrochemistry, [CHIM]Chemical Sciences, General Materials Science, Lipid bilayer, Spectroscopy, chemistry.chemical_classification, [PHYS]Physics [physics], Small-angle X-ray scattering, Biomolecule, Surfaces and Interfaces, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, chemistry, Chemical engineering, Microscopy, Electron, Scanning, Nanoparticles, Spectrophotometry, Ultraviolet, 0210 nano-technology
Abstract: International audience; Self-organization of fluorescent nanoparticles, using biological molecules such as phospholipids to control assembly distances, is a promising method for creating hybrid nanostructures. We report here the formation of hybrid condensed phases made of anisotropic nanoparticles and phospholipids. Such structure formation is driven by electrostatic interaction between the nanoparticles and the phospholipids, and results in the formation of a 2D rectangular liquid crystal, as confirmed by high-resolution Small-Angle X-ray Scattering (SAXS). Moreover, we show that the fluorescent properties of the NPs are not modified by the self-assembly process
Published: 2015

23. Spontaneous and field-induced mesomorphism of a silyl-terminated bent-core liquid crystal as determined from second-harmonic generation and resonant X-ray scattering

Author: LiDong Pan, K. Geese, P. Barois, Virginie Ponsinet, Ron Pindak, G. Sanz-Enguita, Josu Ortega, César L. Folcia, Z. Q. Liu, Sofía Rodríguez-Conde, Jesús Etxebarria, Carsten Tschierske, B. K. McCoy, Cheng-Cher Huang, Department of Condensed Matter Physics, University of the Basque Country [Bizkaia] (UPV/EHU), Departement of Applied Physics II, Institute of Chemistry, Organic Chemistry Martin-Luther-University, Centre de recherches Paul Pascal (CRPP), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Photon Sciences Directorate, Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Department of Physics and Astronomy [Baltimore], Johns Hopkins University (JHU), School of Physics and Astronomy [Minneapolis], University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, Department of Chemistry and Physics, St. Cloud State University, and Minnesota State Colleges and Universities system-Minnesota State Colleges and Universities system
Subjects: Diffraction, Materials science, Field (physics), Scattering, Second-harmonic generation, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Ferroelectricity, 0104 chemical sciences, Crystallography, Liquid crystal, Electric field, Antiferroelectricity, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], 0210 nano-technology
Abstract: 10 pages; International audience; The polarity and structure of the phases of a liquid crystal constituted by thiophene-based bent-core molecules is investigated by means of optical second-harmonic generation (SHG), and resonant and conventional X-ray diffraction. The material studied is representative of a wide family of mesogens that contain silyl groups at the ends of the chains. These bulky terminal groups have been reported to give rise to smectic phases showing ferroelectric switching. However, the analysis of the SHG signal before and after application of electric fields has allowed us to establish unambiguously that the reported ferroelectricity is not intrinsic to the material but stabilized by the cell substrates once an electric field has been applied. In addition, the results obtained from resonant X-ray diffraction indicate that virgin samples have antiferroelectric undulated synclinic smectic structures.
Published: 2014

24. New insights into the phase diagram of the copper oxide superconductors from electronic Raman scattering

Author: M. A. Méasson, Genda Gu, Dorothée Colson, Maximilien Cazayous, Yann Gallais, Alain Sacuto, Laboratoire Matériaux et Phénomènes Quantiques (MPQ (UMR_7162)), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Brookhaven National Laboratory, Laboratoire Nano-Magnétisme et Oxydes (LNO), Service de physique de l'état condensé (SPEC - UMR3680), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), and State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)
Subjects: Copper oxide, Materials science, FOS: Physical sciences, General Physics and Astronomy, 02 engineering and technology, 01 natural sciences, Superconductivity (cond-mat.supr-con), symbols.namesake, chemistry.chemical_compound, Condensed Matter::Superconductivity, 0103 physical sciences, Cuprate, 010306 general physics, Phase diagram, Superconductivity, [PHYS]Physics [physics], Condensed matter physics, Condensed Matter - Superconductivity, Doping, 021001 nanoscience & nanotechnology, chemistry, symbols, Condensed Matter::Strongly Correlated Electrons, 0210 nano-technology, Pseudogap, Raman spectroscopy, Raman scattering
Abstract: Mechanism of unconventional superconductivity is still unknown even if more than 25 years have been passed since the discovery of high-Tc cuprate superconductors by J.G. Bednorz and K. A. Muller. Here, we explore the cuprate phase diagram by electronic Raman spectroscopy and shed light on the superconducting state in hole doped cuprates. Namely, how superconductivity and the critical temperature Tc are impacted by the pseudogap., Comment: 12 pages 7 figs
Published: 2013

25. Surface phase transitions in BiFeO3 below room temperature

Author: Pavel Cevc, Brahim Dkhil, Marin Alexe, P. Gemeiner, Xavier Marti, Patrick Berthet, James F. Scott, Pilar Ferrer, R. Jarrier, T. Schulli, Michael A. Carpenter, Tae-Jin Park, Stanislaus S. Wong, Julia Herrero-Albillos, Robert Blinc, Grégory Geneste, Raphael Haumont, Gustau Catalan, Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Structures, Propriétés et Modélisation des solides (SPMS), Institut de Chimie du CNRS (INC)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Departement of Physics, Charles University [Prague] (CU), Helmholtz-Zentrum, mATERIALIEN UND eNERGIE gMBH bESSY, Centro Universitario de la Defensa, Centra de Huesca, SpLine (BM25), European Synchrotron Radiation Facility (ESRF), Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Elect Ceramics Department - slovenia, Jozef Stefan Institute [Ljubljana] (IJS), University at Albany - Department of Chemistry, State University of New York (SUNY), Condensed Matter Physics and Materials Sciences Department, Brookhaven National Laboratory [Upton, NY] (BNL), UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE), KAERI, Koerea atomic energy research institut, Max Planck Institute of Microstructure Physics, Department of Earth Sciences [Cambridge, UK], University of Cambridge [UK] (CAM), Cavendish Laboratory, ICREA / CIN2, Universitat Autònoma de Barcelona (UAB), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Charles University [Prague], Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Brookhaven National Laboratory, and Universitat Autònoma de Barcelona [Barcelona] (UAB)
Subjects: Phase transition, Materials science, FOS: Physical sciences, 02 engineering and technology, Dielectric, 01 natural sciences, chemistry.chemical_compound, symbols.namesake, Condensed Matter::Materials Science, Lattice constant, 0103 physical sciences, 010306 general physics, ComputingMilieux_MISCELLANEOUS, Bismuth ferrite, Resonant ultrasound spectroscopy, Condensed Matter - Materials Science, Condensed matter physics, Materials Science (cond-mat.mtrl-sci), Charge density, Resonance, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, Condensed Matter - Other Condensed Matter, chemistry, symbols, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0210 nano-technology, Raman spectroscopy, Other Condensed Matter (cond-mat.other)
Abstract: We combine a wide variety of experimental techniques to analyze two heretofore mysterious phase transitions in multiferroic bismuth ferrite at low temperature. Raman spectroscopy, resonant ultrasound spectroscopy, EPR, X-ray lattice constant measurements, conductivity and dielectric response, specific heat and pyroelectric data have been collected for two different types of samples: single crystals and, in order to maximize surface/volume ratio to enhance surface phase transition effects, BiFeO3 nanotubes were also studied. The transition at T=140.3K is shown to be a surface phase transition, with an associated sharp change in lattice parameter and charge density at the surface. Meanwhile, the 201K anomaly appears to signal the onset of glassy behaviour., submitted to PRB
Published: 2012

26. High harmonic attosecond pulse train amplification in a free electron laser

Author: N.R. Thompson, B. Sheehy, David Dunning, Brian McNeil, Department of Physics, University of Strathclyde [Glasgow], Cockcroft Institute, STFC Daresbury Laboratory, Collider-Accelerator Department, Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), and State University of New York (SUNY)-State University of New York (SUNY)
Subjects: Physics, 42.65.Ky, Klystron, 010308 nuclear & particles physics, business.industry, Attosecond, Free-electron laser, Physics::Optics, Nonlinear optics, Condensed Matter Physics, Laser, 01 natural sciences, 42.65.Re, Atomic and Molecular Physics, and Optics, law.invention, Optics, law, Harmonics, 41.60.Cr, 0103 physical sciences, High harmonic generation, Atomic physics, 010306 general physics, business, Ultrashort pulse
Abstract: International audience; It is shown using three dimensional simulations that the temporal structure of an attosecond pulse train, such as that generated via High Harmonic generation in noble gases, may be retained in a Free Electron Laser amplifier through to saturation using a Mode Locked Optical Klystron configuration. At wavelengths of ∼12 nm, a train of attosecond pulses of widths ∼300 attoseconds with peak powers in excess of 1 GW are predicted.
Published: 2011

27. Resonant x-ray scattering and full polarisation analysis of forbidden half-integer reflections in magnetite

Author: Stuart Wilkins, J. E. Lorenzo, Claudio Mazzoli, S. R. Bland, V. A. M. Brabers, T. A. W. Beale, Blanka Detlefs, Yves Joly, Peter D. Hatton, Simon Brown, Department of Physics, Durham University, European Synchrotron Radiation Facility (ESRF), Brookhaven, Natl Lab., Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Surfaces, Interfaces et Nanostructures (SIN), Institut Néel (NEEL), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Durham University-Okayama University, Magnétisme et Supraconductivité (MagSup), Department of Applied Physics [Eindhoven], and Eindhoven University of Technology [Eindhoven] (TU/e)
Subjects: Diffraction, History, Materials science, 02 engineering and technology, Electronic structure, 01 natural sciences, Education, Crystal, Magnetite, chemistry.chemical_compound, Optics, 0103 physical sciences, 010306 general physics, Resonant x-ray diffraction, Condensed matter physics, business.industry, Scattering, Fe3O4, 021001 nanoscience & nanotechnology, Polarization (waves), Computer Science Applications, Resonant inelastic X-ray scattering, Resonant x-ray scattering, chemistry, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Half-integer, 0210 nano-technology, business
Abstract: 5 pages; International audience; Magnetite is one of the oldest known magnetic materials, but questions still surround both its crystal and electronic structures at low temperature. The most debated of these low temperature properties regard the presence, or lack of, of charge and orbital order. Using resonant x-ray di raction at the iron K-edge to probe the long range order present on the iron sites, we have studied (0 0 2n+1/2 )C type reflections. By using the technique of full linear polarisation, we have shown that the key features of the reflections can be described merely using the simpli ed Pmca structure, without invoking orbital order.
Published: 2010

28. Infrared spectra of individual semiconducting single-walled carbon nanotubes: Testing the scaling of transition energies for large diameter nanotubes

Author: Matthew Y. Sfeir, Robert Caldwell, Christophe Voisin, Bhupesh Chandra, Tony F. Heinz, Yang Wu, Sami Rosenblatt, Hugen Yan, G. L. Carr, Stéphane Berciaud, Yuyao Shan, James A. Misewich, James Hone, Condensed Matter Physics Division, Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Departments of Physics and Electrical Engineering, Columbia University [New York], Laboratoire Pierre Aigrain (LPA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Mechanical Engineering, UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Infrared spectroscopy, Mechanical properties of carbon nanotubes, Nanotechnology, 02 engineering and technology, Carbon nanotube, 01 natural sciences, Molecular physics, law.invention, symbols.namesake, Condensed Matter::Materials Science, law, 0103 physical sciences, Rayleigh scattering, 010306 general physics, Spectroscopy, Condensed Matter::Other, Photoconductivity, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, Electronic, Optical and Magnetic Materials, Optical properties of carbon nanotubes, [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], symbols, Ballistic conduction in single-walled carbon nanotubes, 0210 nano-technology
Abstract: International audience; We have measured the low-energy excitonic transitions of chiral assigned individual large-diameter semiconducting single-walled nanotubes using a high-resolution Fourier transform photoconductivity technique. When photoconductivity is complemented by Rayleigh scattering spectroscopy, as many as five optical transitions can be identified on the same individual nanotube over an energy range of 0.3-2.7 eV. We find that well-established energy scaling relations developed for nanotubes of smaller diameter are not consistent with the measured low-energy transitions in large (1.8-2.3 nm) diameter nanotubes.
Published: 2010

29. Neutron scattering study of the high-energy graphitic phonons in superconducting CaC6

Author: Siddharth S. Saxena, A. Ivanov, Christopher A. Howard, M. Ellerby, Mark Dean, A. C. Walters, T. E. Weller, Matteo Calandra, Francesco Mauri, D. F. McMorrow, Cavendish Laboratory, University of Cambridge [UK] (CAM), Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Brookhaven National Laboratory [Upton, NY] (BNL), UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE), European Synchrotron Radiation Facility (ESRF), Harvard University Biological Laboratories, Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), University College of London [London] (UCL), Institut Laue-Langevin (ILL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, and ILL
Subjects: Phonon, Neutron diffraction, FOS: Physical sciences, 02 engineering and technology, Neutron scattering, 01 natural sciences, Superconductivity (cond-mat.supr-con), Renormalization, Condensed Matter - Strongly Correlated Electrons, Graphite intercalation compound, chemistry.chemical_compound, Condensed Matter::Materials Science, Thermal conductivity, PACS : 71.20.Tx, 63.20.kd, 74.25.Kc, 78.70.Nx, 0103 physical sciences, INTERCALATION COMPOUNDS, Graphite, 010306 general physics, Superconductivity, Physics, Condensed Matter - Materials Science, Research Groups and Centres\Physics\Low Temperature Physics, fisica, Strongly Correlated Electrons (cond-mat.str-el), Condensed matter physics, Faculty of Science\Physics, Condensed Matter - Superconductivity, Materials Science (cond-mat.mtrl-sci), 021001 nanoscience & nanotechnology, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, chemistry, 0210 nano-technology
Abstract: We present the results of a neutron scattering study of the high energy phonons in the superconducting graphite intercalation compound CaC$_6$. The study was designed to address hitherto unexplored aspects of the lattice dynamics in CaC$_6$, and in particular any renormalization of the out-of-plane and in-plane graphitic phonon modes. We present a detailed comparison between the data and the results of density functional theory (DFT). A description is given of the analysis methods developed to account for the highly-textured nature of the samples. The DFT calculations are shown to provide a good description of the general features of the experimental data. This is significant in light of a number of striking disagreements in the literature between other experiments and DFT on CaC$_6$. The results presented here demonstrate that the disagreements are not due to any large inaccuracies in the calculated phonon frequencies., Comment: 5 pages, 4 figures, updated version with changes to figure 4 (Accepted in PRB)
Published: 2010

30. Full polarization analysis of resonant superlattice and forbidden x-ray reflections in magnetite

Author: S. R. Bland, T. A. W. Beale, S.B. Wilkins, Claudio Mazzoli, Yves Joly, J. E. Lorenzo, V. A. M. Brabers, Blanka Detlefs, Peter D. Hatton, Department of Physics, Durham University, European Synchrotron Radiation Facility (ESRF), Brookhaven, Natl Lab., Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Surfaces, Interfaces et Nanostructures (SIN), Institut Néel (NEEL), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Durham University-Okayama University, Magnétisme et Supraconductivité (MagSup), Department of Applied Physics [Eindhoven], and Eindhoven University of Technology [Eindhoven] (TU/e)
Subjects: Diffraction, Condensed matter physics, Linear polarization, Scattering, Chemistry, Superlattice, polarization analysis, Fe3O4, resonant x-ray scattering, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Polarization (waves), 01 natural sciences, Electromagnetic radiation, Magnetite, Charge ordering, 0103 physical sciences, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], General Materials Science, 010306 general physics, 0210 nano-technology, Anisotropy, Resonant x-ray diffraction
Abstract: 9 pages; International audience; Despite being one of the oldest known magnetic materials, and the classic mixed valence compound, thought to be charge ordered, the structure of magnetite below the Verwey transition is complex and the presence and role of charge order is still being debated. Here, we present resonant x-ray diffraction data at the iron K-edge on forbidden (0, 0, 2n + 1)C and superlattice (0, 0, 2n+1/2 )C reflections. Full linear polarization analysis of the incident and scattered light was conducted in order to explore the origins of the reflections. Through simulation of the resonant spectra we have confirmed that a degree of charge ordering takes place, while the anisotropic tensor of susceptibility scattering is responsible for the superlattice reflections below the Verwey transition. We also report the surprising result of the conversion of a significant proportion of the scattered light from linear to nonlinear polarization.
Published: 2009

31. Electronic properties of iron arsenic high temperature superconductors revealed by angle resolved photoemission spectroscopy (ARPES)

Author: Andrés F. Santander-Syro, Chang Liu, German D. Samolyuk, Alexei V. Fedorov, R. T. Gordon, O. Copie, Tonica Valla, Makariy A. Tanatar, Yongbin Lee, Paul C. Canfield, B. N. Harmon, Ruslan Prozorov, N. Ni, M. E. Tillman, S.L. Bud'ko, Eundeok Mun, Ari Palczewski, Eli Rotenberg, Catalin Martin, J. L. McChesney, Joerg Schmalian, Takeshi Kondo, Adam Kaminski, Ames Laboratory [Ames, USA], Iowa State University (ISU)-U.S. Department of Energy [Washington] (DOE), Department of Physics and Astronomy [Ames, Iowa], Iowa State University (ISU), Laboratoire Photons Et Matière, Université Pierre et Marie Curie - Paris 6 (UPMC)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des Solides d'Orsay (LPS), Universirté d'Orsay, Lawrence Berkeley National Laboratory [Berkeley] (LBNL), Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Unité mixte de physique CNRS/Thales (UMPhy CNRS/THALES), Centre National de la Recherche Scientifique (CNRS)-THALES, UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE), and THALES [France]-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], Materials science, High-temperature superconductivity, Condensed matter physics, Fermi level, Energy Engineering and Power Technology, Quantum oscillations, Angle-resolved photoemission spectroscopy, Fermi surface, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas, Electronic, Optical and Magnetic Materials, law.invention, symbols.namesake, law, Condensed Matter::Superconductivity, 0103 physical sciences, symbols, Electrical and Electronic Engineering, 010306 general physics, Fermi gas, Electronic band structure, Pseudogap
Abstract: International audience; We present an overview of the electronic properties of iron arsenic high temperature superconductors with emphasis on low energy band dispersion, Fermi surface and superconducting gap. ARPES data is compared with full-potential linearized plane wave (FLAPW) calculations. We focus on single layer NdFeAsO0.9F0.1 (R1111) and two layer Ba1−xKxFe2As2 (B122) compounds. We find general similarities between experimental data and calculations in terms of character of Fermi surface pockets, and overall band dispersion. We also find a number of differences in details of the shape and size of the Fermi surfaces as well as the exact energy location of the bands, which indicate that magnetic interaction and ordering significantly affects the electronic properties of these materials. The Fermi surface consists of several hole pockets centered at Γ and electron pockets located in zone corners. The size and shape of the Fermi surface changes significantly with doping. Emergence of a coherent peak below the critical temperature Tc and diminished spectral weight at the chemical potential above Tc closely resembles the spectral characteristics of the cuprates, however the nodeless superconducting gap clearly excludes the possibility of d-wave order parameter. Instead it points to s-wave or extended s-wave symmetry of the order parameter.
Published: 2009

32. A critical re-examination of resonant soft x-ray Bragg forbidden reflections in magnetite

Author: Stuart Wilkins, Peter Bencok, Yves Joly, T. A. W. Beale, V. A. M. Brabers, Flora Yakhou, Claudio Mazzoli, Peter D. Hatton, S. Di Matteo, Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Surfaces et interfaces, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Department of Physics [Durham University], Durham University, Surfaces, Interfaces et Nanostructures (SIN), Institut Néel (NEEL), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), Department of Applied Physics [Eindhoven], Eindhoven University of Technology [Eindhoven] (TU/e), Physics of Nanostructures, UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), and Surfaces, Interfaces et Nanostructures (NEEL - SIN)
Subjects: Diffraction, heavy fermions, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, 02 engineering and technology, 01 natural sciences, Condensed Matter - Strongly Correlated Electrons, 0103 physical sciences, Sensitivity (control systems), 010306 general physics, Physics, Condensed matter physics, Strongly Correlated Electrons (cond-mat.str-el), Scattering, 71.27.+a, Charge (physics), Strongly correlated electron systems, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, Reflection (mathematics), [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], X-ray crystallography, Strongly correlated material, Atomic physics, 0210 nano-technology, Single crystal
Abstract: Magnetite, Fe$_3$O$_4$, displays a highly complex low temperature crystal structure that may be charge and orbitally ordered. Many of the recent experimental claims of such ordering rely on resonant soft x-ray diffraction at the oxygen K and iron L edges. We have re-examined this system and undertaken soft x-ray diffraction experiments on a high-quality single crystal. Contrary to previous claims in the literature, we show that the intensity observed at the Bragg forbidden (001/2)$_c$ reflection can be explained purely in terms of the low-temperature structural displacements around the resonant atoms. This does not necessarily mean that magnetite is not charge or orbitally ordered, but rather that the present sensitivity of resonant soft x-ray experiments does not allow conclusive demonstration of such ordering., Comment: 5 pages, 3 figures
Published: 2008
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33. Surface effects on the orbital order in the single layered manganite La0.5 Sr1.5 MnO4

Author: Alan I. Goldman, John Hill, Yusuke Wakabayashi, Philip Ryan, Hong Zheng, Stéphane Grenier, C.S. Nelson, John F. Mitchell, Mary Upton, Jaeyoun Kim, Photon Factory, High Energy Accelerator Research Organization, Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Matériaux, Rayonnements, Structure (MRS), Institut Néel (NEEL), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), National Synchrotron Light Source (NSLS), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), Ames Laboratory [Ames, USA], Iowa State University (ISU)-U.S. Department of Energy [Washington] (DOE), Department of Physics and Astronomy [Ames, Iowa], Iowa State University (ISU), and Argonne National Laboratory [Lemont] (ANL)
Subjects: Surface (mathematics), Materials science, Truncation, FOS: Physical sciences, correlated systems, 02 engineering and technology, 01 natural sciences, Rod, Crystal, Condensed Matter - Strongly Correlated Electrons, Condensed Matter::Materials Science, manganite, surface reconstruction, 0103 physical sciences, General Materials Science, orbital ordering, 010306 general physics, Perovskite (structure), Condensed matter physics, Strongly Correlated Electrons (cond-mat.str-el), Scattering, Mechanical Engineering, Order (ring theory), General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Manganite, Mechanics of Materials, Condensed Matter::Strongly Correlated Electrons, [PHYS.COND.CM-SCE]Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el], 0210 nano-technology
Abstract: We report the first observation of `orbital truncation rods' -- the scattering arising from the termination of bulk orbital order at the surface of a crystal. The x-ray measurements, performed on a cleaved, single-layered perovskite, La0.5Sr1.5MnO4, reveal that while the crystallographic surface is atomically smooth, the orbital `surface' is much rougher, with an r.m.s. deviation from the average `surface' of ~0.7nm. The temperature dependence of this scattering shows evidence of a surface-induced second order transition., Comment: 13 pages, 4 figures
Published: 2007

34. Nanoscale Hydration in Layered Manganese Oxides

Author: Jean-François Boily, Eugene S. Ilton, Andrey Shchukarev, Jerry Lindholm, Michael Holmboe, Wei Cheng, N. Tan Luong, Khalil Hanna, Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Umeå University, Pacific Northwest National Laboratory (PNNL), This work was supported by the Swedish Research Council through a grant to J.-F.B. (2016-03808, 2020-04853) and to M.H. (2019-04733) and by the CNRS (PICS 2018-2020) through a grant to J.-F.B and K.H. W.C. was supported by the China Scholarship Council for a Ph.D. grant and by Rennes Métropole (France) for a mobility grant for an extended research visit at Umeå University. K.H. is also supported by Institut Universitaire de France (IUF). E.S.I. was supported by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences (BES), Chemical Sciences, Geosciences, and Biosciences Division through its Geosciences program at the Pacific Northwest National Laboratory (PNNL)., Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)
Subjects: Birnessite, Materials science, Intercalation (chemistry), Hydration, chemistry.chemical_element, Nanoparticle, Manganese, 010501 environmental sciences, 010502 geochemistry & geophysics, 01 natural sciences, Article, Adsorption, Monolayer, Electrochemistry, [CHIM]Chemical Sciences, Molecule, General Materials Science, structure, manganese oxide, Spectroscopy, 0105 earth and related environmental sciences, Geokemi, nanoscale, Surfaces and Interfaces, Condensed Matter Physics, Geochemistry, chemistry, Chemical engineering, Water vapor
Abstract: Birnessite is a layered MnO2 mineral capable of intercalating nanometric water films in its bulk. With its variable distributions of Mn oxidation states (MnIV, MnIII, and MnII), cationic vacancies, and interlayer cationic populations, birnessite plays key roles in catalysis, energy storage solutions, and environmental (geo)chemistry. We here report the molecular controls driving the nanoscale intercalation of water in potassium-exchanged birnessite nanoparticles. From microgravimetry, vibrational spectroscopy, and X-ray diffraction, we find that birnessite intercalates no more than one monolayer of water per interlayer when exposed to water vapor at 25 °C, even near the dew point. Molecular dynamics showed that a single monolayer is an energetically favorable hydration state that consists of 1.33 water molecules per unit cell. This monolayer is stabilized by concerted potassium–water and direct water–birnessite interactions, and involves negligible water–water interactions. Using our composite adsorption–condensation–intercalation model, we predicted humidity-dependent water loadings in terms of water intercalated in the internal and adsorbed at external basal faces, the proportions of which vary with particle size. The model also accounts for additional populations condensed on and between particles. By describing the nanoscale hydration of birnessite, our work secures a path for understanding the water-driven catalytic chemistry that this important layered manganese oxide mineral can host in natural and technological settings. Originally included in thesis in manuscript form.
Published: 2021

35. Characterization of dislocations in protein crystals by means of synchrotron double-crystal topography

Author: Jürgen Härtwig, Yves Epelboin, A. B. Moraleda, Fermín Otálora, Vivian Stojanoff, B. Capelle, Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), LEC (IACT), Campus Fuentenueva (Fac. Ciencias), Universidad de Granada = University of Granada (UGR), Brookhaven National Laboratory [Upton, NY] (BNL), UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Universidad de Granada (UGR), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), and State University of New York (SUNY)-State University of New York (SUNY)
Subjects: Diffraction, Topography, Synchrotron radiation, Dislocations, 02 engineering and technology, DIFFRACTION, 01 natural sciences, General Biochemistry, Genetics and Molecular Biology, law.invention, Condensed Matter::Materials Science, law, 0103 physical sciences, Crystallization, Macromolecular crystallography, 010302 applied physics, Condensed matter physics, Chemistry, Protein crystallography, 021001 nanoscience & nanotechnology, Synchrotron, Crystallography, Hen egg-white lysozyme, X-ray crystallography, TETRAGONAL LYSOZYME, GROWTH, RADIATION, X-RAY TOPOGRAPHY, CRYSTALLIZATION, 0210 nano-technology, Protein crystallization, Burgers vector, Beam (structure)
Abstract: 5 pages, 8 figures., Hen egg-white lysozyme (HEWL) crystals have been studied by means of double-crystal synchrotron topography. The crystals reveal a number of features that are quite well known in hydrothermally grown inorganic crystals: dislocations, growth bands and growth sector boundaries. Dislocations in the sectors have been characterized as edge dislocations with Burgers vector parallel to the c axis. They are distinguishable only under weak beam conditions. The presence of edge dislocations shown in this paper is consistent with the spiral growth steps previously reported. This spiral growth on protein crystals has been observed many times by surface techniques., We are very indebted to Dr M. C. Robert who kindly helped us to examine the topographs and to analyse the various features of their contrast.
Published: 2004

36. Definition of a new (Doniach‐Sunjic‐Shirley) peak shape for fitting asymmetric signals applied to reduced graphene oxide/graphene oxide XPS spectra

Author: David J. Morgan, Vincent Fernandez, Behnam Moeini, Jonas Baltrusaitis, Peter J. Cumpson, Matthew R. Linford, Anders J. Barlow, Neal Fairley, Brigham Young University (BYU), Casa Software Ltd, La Trobe University [Melbourne], University of New South Wales [Sydney] (UNSW), Cardiff University, HarwellXPS EPSRC, Institut des Matériaux Jean Rouxel (IMN), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN), Lehigh University [Bethlehem], and U.S. Department of Energy (Office of Science, Office of Basic Energy Sciences and Energy Efficiency and Renewable Energy, Solar Energy Technology Program), Grant/Award Number: DE-SC0012577
Subjects: Surface (mathematics), media_common.quotation_subject, Oxide, 02 engineering and technology, 01 natural sciences, Asymmetry, Spectral line, law.invention, chemistry.chemical_compound, X-ray photoelectron spectroscopy, law, 0103 physical sciences, Materials Chemistry, media_common, 010302 applied physics, Basis (linear algebra), Condensed matter physics, Graphene, Surfaces and Interfaces, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Surfaces, Coatings and Films, chemistry, Line (geometry), [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0210 nano-technology
Abstract: International audience; The existence of asymmetry in X-ray photoelectron spectroscopy (XPS) photoemission lines is widely accepted, but line shapes designed to accommodate asymmetry are generally lacking in theoretical justification. In this work, we present a new line shape for describing asymmetry in XPS signals that is based on two facts. First, the most widely known line shape for fitting asymmetric XPS signals that has a theoretical basis, referred to as the Doniach-Sunjic (DS) line shape, suffers from a mathematical inconvenience, which is that for asymmetric shapes the area beneath the curve (above the x-axis) is infinite. Second, it is common practice in XPS to remove the inelastically scattered background response of a peak in question with the Shirley algorithm. The new line shape described herein attempts to retain the theoretical virtues of the DS line shape, while allowing the use of a Shirley background, with the consequence that the resulting line shape has a finite area. To illustrate the use of this Doniach-Sunjic-Shirley (DSS) line shape, a set of spectra obtained from varying amounts of graphene oxide (GO) and reduced GO on a patterned, heterogeneous surface are fit and discussed.
Published: 2021

37. Ubiquity of amplitude-modulated magnetic ordering in the $H − T$ phase diagram of the frustrated non-Fermi-liquid YbAgGe

Author: Garry J. McIntyre, Ch. Rüegg, D. F. McMorrow, Oksana Zaharko, C. B. Larsen, B. Fåk, Eric Ressouche, S.L. Bud'ko, D. G. Mazzone, Emmanuel Canévet, P. C. Canfield, Laboratory for Neutron Scattering and Imaging [Paul Scherrer Institute] (LNS), Paul Scherrer Institute (PSI), Department of Quantum Matter Physics [Geneva] (DQMP), University of Geneva [Switzerland], London Centre for Nanotechnology, University College of London [London] (UCL), Institut Laue-Langevin (ILL), ILL, Magnétisme et Diffusion Neutronique (MDN ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Ames Laboratory [Ames, USA], Iowa State University (ISU)-U.S. Department of Energy [Washington] (DOE), the Swiss National Science Foundation (Grant No. 200020-182536), and Université de Genève = University of Geneva (UNIGE)
Subjects: Physics, Condensed matter physics, Neutron diffraction, 02 engineering and technology, Electron, 021001 nanoscience & nanotechnology, Thermal conduction, 01 natural sciences, Magnetic field, Amplitude, 0103 physical sciences, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Fermi liquid theory, 010306 general physics, 0210 nano-technology, Anisotropy, Phase diagram
Abstract: International audience; YbAgGe contains a magnetic geometrically frustrated kagome-like lattice that also features significant local single-ion anisotropy. The electronic state is established by hybridization of $4f$ and conduction electrons leading to heavy electronic masses. The competition between these various interactions leads to nontrivial behavior under external magnetic field, including a sequence of magnetic phase transitions, non-Fermi-liquid states, and possibly a quantum critical point. We present a series of neutron diffraction experiments performed in the mK temperature range and under magnetic fields up to 8 T in the hexagonal plane, revealing the microscopic nature of the first four subsequent magnetic states of this phase diagram. The magnetic phases are associated with the propagation vectors $k_1$ = (${1\over 3}$ 0 ${1\over 3}$) for $H$ < 2 T, $k_2$ = (0 0 0.32) for 2 T < $H$ < 3 T, $k_1$ = (${1\over 3}$ 0 ${1\over 3}$) for 3 T < $H$ < 4.5 T, and $k_3$ = (0.195 0.195 0.38) for 4.5 T < $H$ < 7 T. Our structural refinements reveal a strong modulation of the magnetic moment amplitude in all phases. We observe that the ordered moments of the three magnetically different Yb sites become increasingly different in field, which complies with the principle local anisotropy directions relative to the field direction. While the ordered moments are aligned predominantly in the hexagonal plane, we also find a significant out-of-plane component and a ferromagnetic contribution above 2 T. We discuss possible scenarios that may evolve around the phase boundary at 4.5 T, which is associated with putative quantum criticality as identified by various bulk probes. We propose further steps that are required to better understand the microscopic interactions in this material.
Published: 2021

38. Measuring magnetic flux suppression in high-power laser-plasma interactions

Author: P. T. Campbell, C. A. Walsh, B. K. Russell, J. P. Chittenden, A. Crilly, G. Fiksel, L. Gao, I. V. Igumenshchev, P. M. Nilson, A. G. R. Thomas, K. Krushelnick, L. Willingale, AWE Plc, Lawrence Livermore National Laboratory, and U.S Department of Energy
Subjects: Science & Technology, Physics, Fluids & Plasmas, FOS: Physical sciences, Condensed Matter Physics, FIELDS, 7. Clean energy, 01 natural sciences, Physics - Plasma Physics, 0203 Classical Physics, 010305 fluids & plasmas, Plasma Physics (physics.plasm-ph), Physics, Fluids & Plasmas, TRANSPORT-COEFFICIENTS, Physical Sciences, 0201 Astronomical and Space Sciences, 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics, 0103 physical sciences, 010306 general physics, GENERATION
Abstract: Biermann battery magnetic field generation driven by high power laser-solid interactions is explored in experiments performed with the OMEGA EP laser system. Proton deflectometry captures changes to the strength, spatial profile, and temporal dynamics of the self-generated magnetic fields as the target material or laser intensity is varied. Measurements of the magnetic flux during the interaction are used to help validate extended magnetohydrodynamic (MHD) simulations. Results suggest that kinetic effects cause suppression of the Biermann battery mechanism in laser-plasma interactions relevant to both direct and indirect-drive inertial confinement fusion. Experiments also find that more magnetic flux is generated as the target atomic number is increased, which is counter to a standard MHD understanding., 9 pages, 5 figures
Published: 2021

39. Giant Magnetoelectric Coupling and Magnetic-Field-Induced Permanent Switching in a Spin Crossover Mn(III) Complex

Author: Grace G. Morgan, Xiaxin Ding, Vivien Zapf, Hai-Ping Cheng, Jie-Xiang Yu, Shalinee Chikara, Conor T. Kelly, Franziska Weickert, Elzbieta Trzop, Vibe B. Jakobsen, Emiel Dobbelaar, Eric Collet, University College Dublin [Dublin] (UCD), Los Alamos National Laboratory (LANL), University of Florida [Gainesville] (UF), Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), The scientific work by V.S.Z., H.P.C. and J.Y. was funded by the Center for Molecular Magnetic Quantum Materials (M2QM), an Energy Frontier Research Center funded by the U.S. Depart-ment of Energy, Office of Science, Basic Energy Sciences under Award DE SC0019330. G.G.M. would like to thank Science Foundation Ireland (SFI) for support via an Investigator Project Award (19/FFO/6909). V.B.J. was supported by the Irish Re-search Council GOIPG/2016/73 fellowship. Travel grants for V.B.J.’s research visits to LANL and IPR were funded by Augusti-nus Fonden (grant no. 18-0338), Oticon Fonden (grant no. 17-3813), Reinholdt W. Jorck og Hustrus Fond (grant no. 18-JI-0573), P.A. Fiskers Fond, A.P. Møller og Hustru Chastine Mc-Kinney Møllers Fond til almene Formaal and Christian og Ot-tilia Brorsons Rejselegat for yngre videnskabsmænd og -kvinder. C.T.K was supported by the Irish Research Council GOIPG/2018/2510 and UCD Advance PhD Scheme Supple-mental Award. The NHMFL experimental facility at LANL is funded by the U.S. National Science Foundation through Coop-erative Grant No. DMR-1157490, the State of Florida, and the U.S. Department of Energy., and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], Phase transition, Field (physics), Condensed matter physics, 010405 organic chemistry, Chemistry, Magnetoelectric effect, 010402 general chemistry, 01 natural sciences, 0104 chemical sciences, Magnetic field, Inorganic Chemistry, Polarization density, Spin crossover, Phase (matter), [CHIM.COOR]Chemical Sciences/Coordination chemistry, Physical and Theoretical Chemistry, Spin-½
Abstract: International audience; We investigate giant magnetoelectric coupling at a Mn spin crossover in [MnL]BPh (L = (3,5-diBr-sal)323) with a field-induced permanent switching of the structural, electric, and magnetic properties. An applied magnetic field induces a first-order phase transition from a high spin/low spin (HS-LS) ordered phase to a HS-only phase at 87.5 K that remains after the field is removed. We observe this unusual effect for DC magnetic fields as low as 8.7 T. The spin-state switching driven by the magnetic field in the bistable molecular material is accompanied by a change in electric polarization amplitude and direction due to a symmetry-breaking phase transition between polar space groups. The magnetoelectric coupling occurs due to a γη coupling between the order parameter γ related to the spin-state bistability and the symmetry-breaking order parameter η responsible for the change of symmetry between polar structural phases. We also observe conductivity occurring during the spin crossover and evaluate the possibility that it results from conducting phase boundaries. We perform ab initio calculations to understand the origin of the electric polarization change as well as the conductivity during the spin crossover. Thus, we demonstrate a giant magnetoelectric effect with a field-induced electric polarization change that is 1/10 of the record for any material.
Published: 2021

40. A NEXAFS Study of Thin Polyacrylonitrile Films Electrochemically Deposited on Ni: The Effect of the Film Thickness and Annealing Treatment

Author: Pascal Viel, Cécile Reynaud, Gérard Tourillon, N. Lazarz, Michèle Raynaud, Gérard Lécayon, R.F. Garrett, Laboratoire pour l'utilisation du rayonnement électromagnétique (LURE), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-MENRT-Centre National de la Recherche Scientifique (CNRS), Brookhaven National Laboratory Mational Synchrotron Light Source (BNL NSLS), Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Service de Recherche sur les Surface et l'Irradiation de la Matière (SRSIM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Département de Physico-Chimie (DPC), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), and State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE)
Subjects: Annealing (metallurgy), Inorganic chemistry, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, chemistry.chemical_compound, Materials Chemistry, Electrochemistry, Thin film, Electroplating, chemistry.chemical_classification, Renewable Energy, Sustainability and the Environment, Polyacrylonitrile, Polymer, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 6. Clean water, XANES, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Surface coating, chemistry, Chemical engineering, Polymerization, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0210 nano-technology
Abstract: International audience; Polyacrylonitrile (PAN) thin films electrochemically deposited on Ni have been studied by near edge x‐ray absorption fine structure, as a function of the film thickness and annealing treatment. For 20Å thick films, the polymer chains are oriented perpendicular to the surface with the C≡N groups parallel to it. Below a few angstroms, no polymerization occurs but molecules are adsorbed perpendicular to the surface. Annealing at 300°C results in the loss of the majority part of the N content of the film in contrast with the admitted mechanism for bulk PAN.
Published: 1990

41. Investigating radiatively driven, magnetized plasmas with a university scale pulsed-power generator

Author: Halliday, JWD, Crilly, A, Chittenden, J, Mancini, RC, Merlini, S, Rose, S, Russell, DR, Suttle, LG, Valenzuela-Villaseca, V, Bland, SN, Lebedev, SV, U.S Department of Energy, and Defense Threat Reduction Agency
Subjects: physics.plasm-ph, Fluids & Plasmas, 0201 Astronomical and Space Sciences, 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics, Condensed Matter Physics, 0203 Classical Physics
Abstract: We present first results from a novel experimental platform that is able to access physics relevant to topics including indirect-drive magnetized inertial confinement fusion, laser energy deposition, various topics in atomic physics, and laboratory astrophysics (for example, the penetration of B-fields into high energy density plasmas). This platform uses the x rays from a wire array Z-pinch to irradiate a silicon target, producing an outflow of ablated plasma. The ablated plasma expands into ambient, dynamically significant B-fields ([Formula: see text]), which are supported by the current flowing through the Z-pinch. The outflows have a well-defined (quasi-1D) morphology, enabling the study of fundamental processes typically only available in more complex, integrated schemes. Experiments were fielded on the MAGPIE pulsed-power generator (1.4 MA, 240 ns rise time). On this machine, a wire array Z-pinch produces an x-ray pulse carrying a total energy of [Formula: see text] over [Formula: see text]. This equates to an average brightness temperature of around [Formula: see text] on-target.
Published: 2022

42. Magnetized directly-driven ICF capsules: increased instability growth from non-uniform laser drive

Author: Aidan Crilly, Jeremy Chittenden, C. A. Walsh, Lawrence Livermore National Laboratory, U.S Department of Energy, and AWE Plc
Subjects: Physics, Nuclear and High Energy Physics, Science & Technology, business.industry, magneto-inertial fusion, Fluids & Plasmas, alternative ignition concepts, Magneto-inertial fusion, Condensed Matter Physics, Laser, Instability, RAYLEIGH-TAYLOR INSTABILITY, law.invention, Optics, Physics, Fluids & Plasmas, law, Physics::Plasma Physics, Physical Sciences, 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics, direct-drive ICF, business, magnetic fields in ICF
Abstract: Simulations anticipate increased perturbation growth from non-uniform laser heating for magnetized direct-drive implosions. At the capsule pole, where the magnetic field is normal to the ablator surface, the field remains in the conduction zone and suppresses non-radial thermal conduction; in unmagnetized implosions this non-radial heat-flow is crucial in mitigating laser heating imbalances. Single-mode simulations show the magnetic field particularly amplifying short wavelength perturbations, whose behavior is dominated by thermal conduction. The most unstable wavelength can also become shorter. 3D multi-mode simulations of the capsule pole reinforce these findings, with increased perturbation growth anticipated across a wide range of scales. The results indicate that high-gain spherical direct-drive implosions require greater constraints on the laser heating uniformity when magnetized.
Published: 2020

43. Universal relationship between the energy scales of the pseudogap phase, the superconducting state, and the charge-density-wave order in copper oxide superconductors

Author: Indranil Paul, A. Forget, Yann Gallais, N. Auvray, Maximilien Cazayous, Alain Sacuto, Marcello Civelli, G. D. Gu, Dorothée Colson, B. Loret, Laboratoire Matériaux et Phénomènes Quantiques (MPQ (UMR_7162)), Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Brookhaven National Laboratory [Upton, NY] (BNL), UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE), Laboratoire Nano-Magnétisme et Oxydes (LNO), Service de physique de l'état condensé (SPEC - UMR3680), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des Solides (LPS), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), and Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)
Subjects: Copper oxide, FOS: Physical sciences, 02 engineering and technology, 7. Clean energy, 01 natural sciences, Superconductivity (cond-mat.supr-con), chemistry.chemical_compound, Condensed Matter::Superconductivity, 0103 physical sciences, Cuprate, 010306 general physics, ComputingMilieux_MISCELLANEOUS, Physics, Superconductivity, Condensed matter physics, Condensed Matter - Superconductivity, Order (ring theory), State (functional analysis), 021001 nanoscience & nanotechnology, chemistry, Condensed Matter::Strongly Correlated Electrons, [PHYS.COND.CM-SCE]Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el], 0210 nano-technology, Pseudogap, Charge density wave, Energy (signal processing)
Abstract: We report the hole doping dependencies of the pseudogap phase energy scale, $2\Delta_{\rm PG}$, the anti-nodal (nodal) superconducting energy scales $2\Delta^{AN}_{\rm SC}$ ($2\Delta^{N}_{\rm SC}$) and the charge density wave energy scale, $2\Delta_{\rm CDW}$. They have been extracted from the electronic Raman responses of distinct copper oxide families. For all the cuprates studied, we reveal universal doping dependencies which suggest that $2\Delta_{\rm PG}$, $2\Delta^{AN}_{\rm SC}$ and $2\Delta_{\rm CDW}$ are governed by common microscopic interactions and that these interactions become relevant well above the superconducting transition at $T_c$. In sharp contrast, $2\Delta^N_{\rm SC}$ tracks the doping dependence of $T_c$, appearing to be controlled by a different kind of interactions than the energy scales above., Comment: 11 pages and 9 figures
Published: 2020

44. Magnetic field induced structural changes in magnetite observed by resonant x-ray diffraction and Mössbauer spectroscopy

Author: Tomasz Kolodziej, Pavel Novák, Helena Štěpánková, Jan Żukrowski, V. Chlan, P. Babik, Z. Tarnawski, Izabela Bialo, Andrzej Kozłowski, J. E. Lorenzo, E. Wilke, Z. Kąkol, W. Tabiś, Claudio Mazzoli, Yves Joly, R. Řezníček, J. Niewolski, Maciej Zubko, Jurgen M. Honig, K. Łątka, SOLARIS National Synchrotron Radiation Centre, AGH University of Science and Technology [Krakow, PL] (AGH UST), Silesian Center for Education and Interdisciplinary Research, University of Silesia, Uniwersytet Jagielloński w Krakowie = Jagiellonian University (UJ), Magnétisme et Supraconductivité (MagSup), Institut Néel (NEEL), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), European Synchrotron Radiation Facility (ESRF), Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Charles University [Prague] (CU), Leipzig University, CHARLES UNIVERSITY IN PRAGUE FACULTY OF MATHEMATICS AND PHYSICS PRAGUE CZE, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), J. Heyrovský Institute of Physical Chemistry of the ASCR, Czech Academy of Sciences [Prague] (CAS), Surfaces, Interfaces et Nanostructures (SIN), and Purdue University [West Lafayette]
Subjects: Materials science, Condensed matter physics, Scattering, Charge (physics), 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Magnetic field, Magnetization, Charge ordering, 0103 physical sciences, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 010306 general physics, 0210 nano-technology, Spectroscopy, Single crystal, Monoclinic crystal system
Abstract: When a magnetic field is applied to a single crystal of magnetite at $124\phantom{\rule{0.16em}{0ex}}\mathrm{K}gTg50\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, the monoclinic ${c}_{M}$ axis, which is the easy magnetization axis, switches to one of the ⟨100⟩ cubic directions, nearest to the direction of the magnetic field, and the phenomenon known as an axis switching (AS) occurs. A global symmetry probe, resonant x-ray scattering, and a local probe, M\"ossbauer spectroscopy, are used to better understand the mechanism of axis switching. The behavior of three subsystems ordered below the Verwey transition temperature ${T}_{V}$, i.e., lattice distortion, an orbital, and charge orderings, was observed via resonant x-ray scattering as a function of an external magnetic field. This was preceded by calculation of selected peak intensities using the fdmnes code. The M\"ossbauer spectroscopy studies confirmed that the magnetic field triggers electronic rearrangements and atomic displacements. The structure observed after the process of axis switching is very similar to the one obtained after cooling below ${T}_{V}$ with the magnetic field applied along one of the initial ⟨100⟩ cubic directions and distinct from the cooling in the absence of a magnetic field. From all the experimental observations of the phenomenon done so far, it is clear that AS starts from the fluctuations between octahedral iron orbitals that ultimately lead to the Verwey transition, but also to the higher-temperature trimeron dynamics. Therefore, further observation of the axis switching may be a key point to the understanding of a majority of strongly correlated electronic behavior in magnetite as well as in other transition metal oxides.
Published: 2020

45. Extended-magnetohydrodynamics in under-dense plasmas

Author: Jeremy Chittenden, Christopher Walsh, D. W. Hill, Christopher Ridgers, Engineering & Physical Science Research Council (EPSRC), and U.S Department of Energy
Subjects: Physics, Range (particle radiation), Fluids & Plasmas, Plasma, Condensed Matter Physics, Kinetic energy, 01 natural sciences, Measure (mathematics), Magnetic flux, 010305 fluids & plasmas, Computational physics, 0203 Classical Physics, symbols.namesake, Physics::Plasma Physics, 0103 physical sciences, 0201 Astronomical and Space Sciences, 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics, symbols, Electron temperature, Nernst equation, Magnetohydrodynamics, 010306 general physics
Abstract: Extended-magnetohydrodynamics (MHD) transports magnetic flux and electron energy in high-energy-density experiments, but individual transport effects remain unobserved experimentally. Two factors are responsible in defining the transport: electron temperature and electron current. Each electron energy transport term has a direct analog in magnetic flux transport. To measure the thermally driven transport of magnetic flux and electron energy, a simple experimental configuration is explored computationally using a laser-heated pre-magnetized under-dense plasma. Changes to the laser heating profile precipitate clear diagnostic signatures from the Nernst, cross-gradient-Nernst, anisotropic conduction, and Righi-Leduc heat-flow. With a wide operating parameter range, this configuration can be used in both small and large scale facilities to benchmark MHD and kinetic transport in collisional/semi-collisional, local/non-local, and magnetized/unmagnetized regimes.
Published: 2020

46. A Primer on Pulsed Power and Linear Transformer Drivers for High Energy Density Physics Applications

Author: Joshua J. Leckbee, Dale Welch, J. C. Zier, P. C. Campbell, Ryan D. McBride, John Greenly, Aaron Covington, Ronald M. Gilgenbach, B. M. Kovalchuk, Brendan Sporer, J. M. Woolstrum, Akash Shah, Yue Ying Lau, S. M. Miller, S. N. Bland, D. V. Rose, Joseph W. Schumer, Brian Hutsel, Pierre-Alexandre Gourdain, Salvador Portillo, David Yager-Elorriaga, William A. Stygar, A.A. Kim, Bryan V. Oliver, A. M. Steiner, Farhat Beg, Nicholas M. Jordan, Yitzhak Maron, Michael G. Mazarakis, Nicholas Ramey, S. C. Bott-Suzuki, Mark E. Savage, Mark L. Kiefer, Daniel Sinars, George Laity, R. B. Spielman, M. R. Gomez, S. G. Patel, J. D. Douglass, M. E. Cuneo, AWE Plc, Sandia National Laboratories, and U.S Department of Energy
Subjects: Nuclear and High Energy Physics, High energy density physics, Fluids & Plasmas, 0906 Electrical And Electronic Engineering, Pulsed power, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas, law.invention, 0202 Atomic, Molecular, Nuclear, Particle And Plasma Physics, law, 0103 physical sciences, Systems engineering, 010306 general physics, Transformer
Abstract: The objectives of this tutorial are as follows: 1) to help students and researchers develop a basic understanding of how pulsed-power systems are used to create high-energy-density (HED) matter; 2) to develop a basic understanding of a new, compact, and efficient pulsed-power technology called linear transformer drivers (LTDs); 3) to understand why LTDs are an attractive technology for driving HED physics (HEDP) experiments; 4) to contrast LTDs with the more traditional Marx-generator/pulse-forming-line approach to driving HEDP experiments; and 5) to briefly review the history of LTD technology as well as some of the LTD-driven HEDP research presently underway at universities and research laboratories across the globe. This invited tutorial is part of the Mini-Course on Charged Particle Beams and High-Powered Pulsed Sources, held in conjunction with the 44th International Conference on Plasma Science in May of 2017.
Published: 2018

47. Study of the Au-Cr bilayer system using X-ray reflectivity, GDOES, and ToF-SIMS

Author: Nargish Aneshwari, Patrick Chapon, Mourad Idir, Philippe Jonnard, Mangalika Sinha, Mohammed H. Modi, Karine Le Guen, Anouk Galtayries, Laboratoire de Chimie Physique - Matière et Rayonnement (LCPMR), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Raja Ramanna Centre for Advanced Technology, Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), HORIBA France SAS [Longjumeau], HORIBA Scientific [France], Institut de Recherche de Chimie Paris (IRCP), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ministère de la Culture (MC)
Subjects: Glow discharge, Materials science, Bilayer, 010401 analytical chemistry, Analytical chemistry, Float glass, 02 engineering and technology, Surfaces and Interfaces, General Chemistry, Substrate (electronics), Surface finish, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, 0104 chemical sciences, Surfaces, Coatings and Films, law.invention, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, X-ray reflectivity, law, Materials Chemistry, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Thin film, 0210 nano-technology, Layer (electronics)
Abstract: International audience; We study a Au (25 nm)/Cr (10 nm) bilayer system as a model of mirror for the soft X‐ray energy range. The Au and Cr thin films are a few nanometer thick and are deposited on a float glass substrate. The sample is characterized by using 3 complementary techniques: soft X‐ray reflectivity, glow discharge optical emission spectrometry (GDOES), and time‐of‐flight secondary ion mass spectroscopy (ToF‐SIMS). Soft X‐ray reflectivity provides information about the thickness and roughness of the different layers, while GDOES is used to obtain the elemental depth profile of the stack and ToF‐SIMS to obtain the elemental and chemical depth profiles. GDOES and ToF‐SIMS have both a nanometer depth resolution. A coherent description of the bilayer stack is obtained through the combination of these techniques. It consists in 5 layers namely a surface contamination layer, a principal gold layer, a Au‐Cr mixed layer, a Cr layer, and another contamination layer at the top of the substrate.
Published: 2018

48. A Facile Space-Confined Solid-Phase Sulfurization Strategy for Growth of High-Quality Ultrathin Molybdenum Disulfide Single Crystals

Author: Jun Xiao, Zhiyong Xiao, Stephen Ducharme, Xi Huang, Yongfeng Lu, Xia Hong, Fei Wang, Bai Cui, Ying Liu, Sai Mu, Jean-François Silvain, Dawei Li, Jingfeng Song, Lijia Jiang, Lan Jiang, Lei Liu, Department of Electrical Engineering, University of Nebraska [Lincoln], University of Nebraska System-University of Nebraska System, Department of Physics and Astronomy [Lincoln], Materials Science and Technology Division [Oak Ridge], Oak Ridge National Laboratory [Oak Ridge] (ORNL), UT-Battelle, LLC-UT-Battelle, LLC, Nebraska Center for Materials and Nanoscience, School of Mechanical Engineering, Beijing Institute of Technology (BIT), Department of Mechanical and Materials Engineering [University of Nebraska–Lincoln], Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and This research was financially supported by the National Science Foundation (CMMI 1129613, CMMI 126512) and the Nebraska Center for Energy Science Research. The U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under Award No. DE-SC0016153 (scanning probe studies, device fabrication, and electrical characterizations).
Subjects: Materials science, chemistry.chemical_element, Bioengineering, Nanotechnology, 02 engineering and technology, Chemical vapor deposition, 010402 general chemistry, 01 natural sciences, chemistry.chemical_compound, Rapid thermal processing, Phase (matter), Monolayer, General Materials Science, Molybdenum disulfide, Mechanical Engineering, Sum-frequency generation, Heterojunction, [CHIM.MATE]Chemical Sciences/Material chemistry, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, chemistry, Molybdenum, 0210 nano-technology, Single crystal
Abstract: International audience; Single-crystal transition metal dichalcogenides (TMDs) and TMD-based heterojunctions have recently attracted significant research and industrial interest owing to their intriguing optical and electrical properties. However, the lack of a simple, low-cost, environmentally friendly, synthetic method and a poor understanding of the growth mechanism post a huge challenge to implementing TMDs in practical applications. In this work, we developed a novel approach for direct formation of high-quality, monolayer and few-layer MoS2 single crystal domains via a single-step rapid thermal processing of a sandwiched reactor with sulfur and molybdenum (Mo) film in a confined reaction space. An all-solid-phase growth mechanism was proposed and experimentally/theoretically evidenced by analyzing the surface potential and morphology mapping. Compared with the conventional chemical vapor deposition approaches, our method involves no complicated gas-phase reactant transfer or reactions and requires very small amount of solid precursors [e.g., Mo (∼3 μg)], no carrier gas, no pretreatment of the precursor, no complex equipment design, thereby facilitating a simple, low-cost, and environmentally friendly growth. Moreover, we examined the symmetry, defects, and stacking phase in as-grown MoS2 samples using simultaneous second-harmonic-/sum-frequency-generation (SHG/SFG) imaging. For the first time, we observed that the SFG (peak intensity/position) polarization can be used as a sensitive probe to identify the orientation of TMDs’ crystallographic axes. Furthermore, we fabricated ferroelectric programmable Schottky junction devices via local domain patterning using the as-grown, single-crystal monolayer MoS2, revealing their great potential in logic and optoelectronic applications. Our strategy thus provides a simple, low-cost, and scalable path toward a wide variety of TMD single crystal growth and novel functional device design.
Published: 2018

49. RF compressibility of topological surface and interface states in metal–hBN–Bi 2 Se 3 capacitors

Author: Kenji Watanabe, José Palomo, T. Taniguchi, Gwendal Fève, T Wilde, Bernard Plaçais, J. Duffy, Jean-Marc Berroir, A. Inhofer, Erwann Bocquillon, Mohamed Boukhicha, Badih A. Assaf, Laboratoire de physique de l'ENS - ENS Paris (LPENS (UMR_8023)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Université Paris Diderot - Paris 7 (UPD7), Northeastern University [Boston], Brookhaven National Laboratory [Upton, NY] (BNL), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), National Institute for Materials Science (NIMS), Physique Mésoscopique, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Université Paris Diderot - Paris 7 (UPD7)-École normale supérieure - Paris (ENS Paris), University of Notre Dame [Indiana] (UND), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Brookhaven National Laboratory [Upton] (BNL), Stony Brook University [SUNY] (SBU), and Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS)
Subjects: Surface (mathematics), Materials science, Interface (Java), FOS: Physical sciences, 02 engineering and technology, 01 natural sciences, law.invention, Metal, Quantum capacitance, symbols.namesake, law, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), 0103 physical sciences, General Materials Science, 010306 general physics, ComputingMilieux_MISCELLANEOUS, [PHYS.COND.CM-MSQHE]Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall], Condensed Matter - Materials Science, Condensed Matter - Mesoscale and Nanoscale Physics, Condensed matter physics, Materials Science (cond-mat.mtrl-sci), 021001 nanoscience & nanotechnology, Condensed Matter Physics, Atomic and Molecular Physics, and Optics, Capacitor, Dirac fermion, Topological insulator, visual_art, Compressibility, visual_art.visual_art_medium, symbols, 0210 nano-technology
Abstract: The topological state that emerges at the surface of a topological insulator (TI) and at the TI-substrate interface are studied in metal-hBN-Bi2Se3 capacitors. By measuring the RF admittance of the capacitors versus gate voltage, we extract the compressibility of the Dirac state located at a gated TI surface. We show that even in the presence of an ungated surface that hosts a trivial electron accumulation layer, the other gated surface always exhibits an ambipolar effect in the quantum capacitance. We succeed in determining the velocity of surface Dirac fermions in two devices, one with a passivated surface and the other with a free surface that hosts trivial states. Our results demonstrate the potential of RF quantum capacitance techniques to probe surface states of systems in the presence of a parasitic density-of-states., Comment: J. Phys.: Mater. Focus on Topological Matter
Published: 2019

50. Coexistence of static and dynamic magnetism in the Kitaev spin liquid material Cu2IrO3

Author: Natalia E. Mordvinova, Jessica L. McChesney, Adam Berlie, Daniel Haskel, Fazel Tafti, Xavier Rocquefelte, Mykola Abramchuk, G. Fabbris, Oleg I. Lebedev, Faranak Bahrami, Eric Kenney, Michael Graf, Carlo U. Segre, Gediminas Simutis, William Lafargue-Dit-Hauret, Stephen Cottrell, Boston College (BC), Illinois Institute of Technology (IIT), Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), ISIS Neutron and Muon Source (ISIS), STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC)-Science and Technology Facilities Council (STFC), Paul Scherrer Institute (PSI), Laboratoire de Microélectronique et de Physique des Semiconducteurs (LaMIPS), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-NXP Semiconductors [France]-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Argonne National Laboratory [Lemont] (ANL), National Science FoundationNational Science Foundation (NSF) [DMR-1708929], Department of EnergyUnited States Department of Energy (DOE), MRCAT member institutions, Agence Nationale de la RechercheFrench National Research Agency (ANR) [ANR-11-EQPX-0020], U.S. Department of Energy (DOE), Office of ScienceUnited States Department of Energy (DOE) [DE-AC02-06CH11357], Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), and ANR-11-EQPX-0020,GENESIS,Groupe d'Etudes et de Nanoanalyses des Effets d'IrradiationS(2011)
Subjects: Kitatev model, Physics, Valence (chemistry), Condensed matter physics, Magnetism, Relaxation (NMR), Honeycomb (geometry), 02 engineering and technology, Quantum spin liquid, Muon spin spectroscopy, 021001 nanoscience & nanotechnology, 01 natural sciences, Muon spin relaxation & rotation, Lattice (order), 0103 physical sciences, [CHIM]Chemical Sciences, 010306 general physics, 0210 nano-technology, Ground state
Abstract: Anyonic excitations emerging from a Kitaev spin liquid can form a basis for quantum computers. Searching for such excitations motivated intense research on the honeycomb iridate materials. However, access to a spin liquid ground state has been hindered by magnetic ordering. Cu2IrO3 is a new honeycomb iridate without thermodynamic signatures of a long-range order. Here, we use muon spin relaxation to uncover the magnetic ground state of Cu2IrO3. We find a two-component depolarization with slow and fast relaxation rates corresponding to distinct regions with dynamic and static magnetism, respectively. X-ray absorption spectroscopy and first principles calculations identify a mixed copper valence as the origin of this behavior. Our results suggest that a minority of Cu2+ ions nucleate regions of static magnetism whereas the majority of Cu+/Ir4+ on the honeycomb lattice give rise to a Kitaev spin liquid.
Published: 2019

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