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Your search keyword '"Sainctavit, Philippe"' showing total 293 results
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293 results on '"Sainctavit, Philippe"'

1. Robust magnetic anisotropy of a monolayer of hexacoordinate Fe( ii ) complexes assembled on Cu(111)

Author

Kelai, Massine, Cahier, Benjamin, Atanasov, Mihail, Neese, Frank, Tong, Yongfeng, Zhang, Luqiong, Bellec, Amandine, Iasco, Olga, Rivière, Eric, Guillot, Régis, Chacon, Cyril, Girard, Yann, Lagoute, Jérôme, Rousset, Sylvie, Repain, Vincent, Otero, Edwige, Arrio, Marie-Anne, Sainctavit, Philippe, Barra, Anne-Laure, Boillot, Marie-Laure, and Mallah, Talal

Subjects
Condensed Matter - Materials Science
Abstract

The tris pyrazolyl borate ligand imposes a rigid scaffold around Fe( ii ) ensuring a robust magnetic anisotropy when the molecules assembled as monolayers suffer from the dissymmetric environment of the substrate/vacuum interface.

Published
2021
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3. Nanoscale distribution of magnetic anisotropies in bimagnetic soft core-hard shell MnFe$_2$O$_4$@CoFe$_2$O$_4$ nanoparticles

Author

Daffé, Niéli, Sikora, Marcin, Rovezzi, Mauro, Bouldi, Nadejda, Gavrilov, Véronica, Neveu, Sophie, Choueikani, Fadi, Ohresser, Philippe, Dupuis, Vincent, Taverna, Dario, Gloter, Alexandre, Arrio, Marie-Anne, Sainctavit, Philippe, and Juhin, Amélie

Subjects
Condensed Matter - Materials Science
Abstract

The nanoscale distribution of magnetic anisotropies was measured in core@shell MnFe$_2$O$_4$@CoFe$_2$O$_4$ 7.0 nm particles using a combination of element selective magnetic spectroscopies with different probing depths. As this picture is not accessible by any other technique, emergent magnetic properties were revealed. The coercive field is not constant in a whole nanospinel. The very thin (0.5 nm) CoFe$_2$O$_4$ hard shell imposes a strong magnetic anisotropy to the otherwise very soft MnFe$_2$O$_4$ core: a large gradient in coercivity was measured inside the MnFe$_2$O$_4$ core with lower values close to the interface region, while the inner core presents a substantial coercive field (0.54 T) and a very high remnant magnetization (90% of the magnetization at saturation)., Comment: 27 pages (including supporting information)

Published
2016
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4. Assembling Fe4 single-molecule magnets on a TiO2 monolayer.

Author

Sorrentino, Andrea Luigi, Poggini, Lorenzo, Serrano, Giulia, Cucinotta, Giuseppe, Cortigiani, Brunetto, Malavolti, Luigi, Parenti, Francesca, Otero, Edwige, Arrio, Marie-Anne, Sainctavit, Philippe, Caneschi, Andrea, Cornia, Andrea, Sessoli, Roberta, and Mannini, Matteo

Published
2024
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5. Quantum dynamics of a single molecule magnet on superconducting Pb(111)

Author

Serrano, Giulia, Poggini, Lorenzo, Briganti, Matteo, Sorrentino, Andrea Luigi, Cucinotta, Giuseppe, Malavolti, Luigi, Cortigiani, Brunetto, Otero, Edwige, Sainctavit, Philippe, Loth, Sebastian, Parenti, Francesca, Barra, Anne-Laure, Vindigni, Alessandro, Cornia, Andrea, Totti, Federico, Mannini, Matteo, and Sessoli, Roberta

Published
2020
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7. Experimental evidence of thermal fluctuations on the X-ray absorption near-edge structure at the aluminum K-edge

Author

Manuel, Damien, Cabaret, Delphine, Brouder, Christian, Sainctavit, Philippe, Bordage, Amélie, and Trcera, Nicolas

Subjects
Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Materials Science
Abstract

After a review of temperature-dependent experimental x-ray absorption near-edge structure (XANES) and related theoretical developments, we present the Al K-edge XANES spectra of corundum and beryl for temperature ranging from 300K to 930K. These experimental results provide a first evidence of the role of thermal fluctuation in XANES at the Al K-edge especially in the pre-edge region. The study is carried out by polarized XANES measurements of single crystals. For any orientation of the sample with respect to the x-ray beam, the pre-edge peak grows and shifts to lower energy with temperature. In addition temperature induces modifications in the position and intensities of the main XANES features. First-principles DFT calculations are performed for both compounds. They show that the pre-edge peak originates from forbidden 1s to 3s transitions induced by vibrations. Three existing theoretical models are used to take vibrations into account in the absorption cross section calculations: i) an average of the XANES spectra over the thermal displacements of the absorbing atom around its equilibrium position, ii) a method based on the crude Born-Oppenheimer approximation where only the initial state is averaged over thermal displacements, iii) a convolution of the spectra obtained for the atoms at the equilibrium positions with an approximate phonon spectral function. The theoretical spectra so obtained permit to qualitatively understand the origin of the spectral modifications induced by temperature. However the correct treatment of thermal fluctuation in XANES spectroscopy requires more sophisticated theoretical tools.

Published
2012
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8. Effect of vibrations on the pre-edge features of x-ray absorption spectra

Author

Brouder, Christian, Cabaret, Delphine, Juhin, Amélie, and Sainctavit, Philippe

Subjects
Condensed Matter - Materials Science
Abstract

The influence of atomic vibrations on x-ray absorption near edge structure (XANES) is calculated by assuming that vibrational energies are small with respect to the instrumental resolution. The resulting expression shows that, at the K-edge, vibrations enable electric dipole transitions to 3s and 3d final states. The theory is applied to the K-edge of Al in Al2O3 corundum and of Ti in TiO2 rutile and compared with experiment. At the Al K-edge, sizeable transitions towards 3s final states are obtained, leading to a clear improvement of the agreement with experimental spectra. At the Ti K-edge, electric dipole transitions towards 3d final states explain the temperature dependence of the pre-edge features., Comment: 4 pages, 2 figures

Published
2009
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9. Room-temperature-persistent magnetic interaction between coordination complexes and nanoparticles in maghemite-based nanohybrids

Author

Curti, Leonardo, primary, Prado, Yoann, additional, Michel, Aude, additional, Talbot, Delphine, additional, Baptiste, Benoît, additional, Otero, Edwige, additional, Ohresser, Philippe, additional, Journaux, Yves, additional, Cartier dit Moulin, Christophe, additional, Dupuis, Vincent, additional, Fleury, Benoit, additional, Sainctavit, Philippe, additional, Arrio, Marie-Anne, additional, Fresnais, Jerome, additional, and Lisnard, Laurent, additional

Published
2024
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10. Orbital Magnetic Moment and Single-Ion Magnetic Anisotropy of the S = 1/2 K3[Fe(CN)6] Compound: A Case Where the Orbital Magnetic Moment Dominates the Spin Magnetic Moment

Author

Retegan, Marius, primary, Jafri, Sadaf Fatima, additional, Curti, Leonardo, additional, Lisnard, Laurent, additional, Otero, Edwige, additional, Rivière, Eric, additional, Haverkort, Maurits W., additional, Bleuzen, Anne, additional, Sainctavit, Philippe, additional, and Arrio, Marie-Anne, additional

Published
2023
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11. X-ray Linear Dichroism in cubic compounds: the case of Cr3+ in MgAl2O4

Author

Juhin, Amélie, Brouder, Christian, Arrio, Marie-Anne, Cabaret, Delphine, Sainctavit, Philippe, Balan, Etienne, Bordage, Amélie, Calas, Georges, Eeckhout, Sigrid G., and Glatzel, Pieter

Subjects
Condensed Matter - Materials Science, Condensed Matter - Strongly Correlated Electrons
Abstract

The angular dependence (x-ray linear dichroism) of the Cr K pre-edge in MgAl2O4:Cr3+ spinel is measured by means of x-ray absorption near edge structure spectroscopy (XANES) and compared to calculations based on density functional theory (DFT) and ligand field multiplet theory (LFM). We also present an efficient method, based on symmetry considerations, to compute the dichroism of the cubic crystal starting from the dichroism of a single substitutional site. DFT shows that the electric dipole transitions do not contribute to the features visible in the pre-edge and provides a clear vision of the assignment of the 1s-->3d transitions. However, DFT is unable to reproduce quantitatively the angular dependence of the pre-edge, which is, on the other side, well reproduced by LFM calculations. The most relevant factors determining the dichroism of Cr K pre-edge are identified as the site distortion and 3d-3d electronic repulsion. From this combined DFT, LFM approach is concluded that when the pre-edge features are more intense than 4 % of the edge jump, pure quadrupole transitions cannot explain alone the origin of the pre-edge. Finally, the shape of the dichroic signal is more sensitive than the isotropic spectrum to the trigonal distortion of the substitutional site. This suggests the possibility to obtain quantitative information on site distortion from the x-ray linear dichroism by performing angular dependent measurements on single crystals.

Published
2008
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12. Structural relaxations around Ti, Cr and Fe impurities in alpha-Al2O3 probed by x-ray absorption near edge structure combined with first-principles calculations

Author

Gaudry, Emilie, Cabaret, Delphine, Sainctavit, Philippe, Brouder, Christian, Mauri, Francesco, Goulon, José, and Rogalev, Andrei

Subjects
Condensed Matter - Materials Science
Abstract

We determine the structural relaxations around paramagnetic impurities (Ti, Cr, Fe) in corundum (alpha-Al2O3), by combining x-ray absorption near edge structure (XANES) experiments and ab initio calculations. The structural relaxations are found to be very local. We then show that XANES is sensitive to small variations in interatomic distances within the coordination shell of the absorbing atom. The experiments were carried out on single crystals of ruby and sapphires. Linear dichroic signals are essential to characterize the geometry of the impurity site. The calculations were performed within a self-consistent ``non muffin-tin'' framework, that uses pseudopotentials, plane-wave basis set, and the continued fraction for the absorption cross section.

Published
2005
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15. Crystal Engineering of Conglomerates: Dilution of Racemate-Forming Fe(II) and Ni(II) Congeners into Conglomerate-Forming [Zn(bpy)3](PF6)2

Author

Serdan, Ugo, primary, Robin, Lucas, additional, Marchivie, Mathieu, additional, Gonidec, Mathieu, additional, Rosa, Patrick, additional, Duverger-Nédellec, Elen, additional, Pouget, Emilie, additional, Sainctavit, Philippe, additional, Arrio, Marie-Anne, additional, Juhin, Amélie, additional, Rogalev, Andrei, additional, Wilhelm, Fabrice, additional, and Hillard, Elizabeth A., additional

Published
2023
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16. X-ray Spectroscopy and Magnetism in Mineralogy

Author

Sainctavit, Philippe, Brice-Profeta, Sandrine, Gaudry, Emilie, Letard, Isabelle, Arrio, Marie-Anne, Beig, R., editor, Beiglböck, W., editor, Domcke, W., editor, Englert, B.-G., editor, Frisch, U., editor, Hänggi, P., editor, Hasinger, G., editor, Hepp, K., editor, Hillebrandt, W., editor, Imboden, D., editor, Jaffe, R. L., editor, Lipowsky, R., editor, Löhneysen, H. v., editor, Ojima, I., editor, Sornette, D., editor, Theisen, S., editor, Weise, W., editor, Wess, J., editor, Zittartz, J., editor, Beaurepaire, Eric, editor, Bulou, Hervé, editor, Scheurer, Fabrice, editor, and Kappler, Jean-Paul, editor

Published
2006
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17. Orbital Magnetic Moment and Single-Ion Magnetic Anisotropy of the S= 1/2 K3[Fe(CN)6] Compound: A Case Where the Orbital Magnetic Moment Dominates the Spin Magnetic Moment

Author

Retegan, Marius, Jafri, Sadaf Fatima, Curti, Leonardo, Lisnard, Laurent, Otero, Edwige, Rivière, Eric, Haverkort, Maurits W., Bleuzen, Anne, Sainctavit, Philippe, and Arrio, Marie-Anne

Abstract

The potassium hexacyanoferrate(III), K3[FeIII(CN)6], is known for its exceptional magnetic anisotropy among the 3d transition metal series. The Fe(III) ions are in the S= 1/2 low spin state imposed by the strong crystal field of the cyanido ligands. A large orbital magnetic moment is expected from previous publications. In the present work, X-ray magnetic circular dichroism was recorded for a powder sample, allowing direct measurement of the Fe(III) orbital magnetic moment. A combination of molecular multiconfigurational ab initio and atomic ligand field multiplets calculations provides the spin and orbital magnetic moments for the [FeIII(CN)6]3−isolated cluster, the crystallographic unit cell, and the powder sample. The calculations of the angular dependencies of the spin and orbital magnetic moments with the external magnetic induction direction reveal easy magnetization axes for each S= 1/2 molecular entity and the crystal. It also shows that the orbital magnetic moment dominates the spin magnetic moment for all directions. Our measurements confirm that the orbital magnetic moment contributes to 60% of the total magnetization for the powder, which is in excellent agreement with our theoretical predictions. An orbital magnetic moment greater than the spin magnetic moment is exceptional for 3d transition metal ions. The impact of crystal field strength and distortion, π back-bonding, spin–orbit coupling, and external magnetic induction was analyzed, leading to a deeper understanding of the spin and orbital magnetic anisotropies.

Published
2023
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19. X-ray Magnetic Circular Dichroism at Low Temperature

Author

Sainctavit, Philippe, Kappler, Jean-Paul, Beig, R., editor, Ehlers, J., editor, Frisch, U., editor, Hepp, K., editor, Hillebrandt, W., editor, Imboden, D., editor, Jaffe, R. L., editor, Kippenhahn, R., editor, Lipowsky, R., editor, v Löhneysen, H., editor, Ojima, I., editor, Weidenmüller, H. A., editor, Wess, J., editor, Zittartz, J., editor, Beaurepaire, Eric, editor, Kappler, Jean Paul, editor, Krill, Gérard, editor, and Scheurer, Fabrice, editor

Published
2001
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23. Strain-engineering of magnetic anisotropy in CoxNi1−x−SrTiO3/SrTiO3 (001) vertically assembled nanocomposites

Author

Weng, Xiaorong, primary, Hennes, Marcel, additional, Juhin, Amélie, additional, Sainctavit, Philippe, additional, Gobaut, Benoit, additional, Otero, Edwige, additional, Choueikani, Fadi, additional, Ohresser, Philippe, additional, Tran, Thomas, additional, Hrabovsky, David, additional, Demaille, Dominique, additional, Zheng, Yunlin, additional, and Vidal, Franck, additional

Published
2022
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24. XAS and XMCD Reveal a Cobalt(II) Imide Undergoes High-Pressure-Induced Spin Crossover

Author

Bouldi, Nadejda, primary, Mannini, Matteo, additional, Retegan, Marius, additional, Miller, Reece G., additional, Cahier, Benjamin, additional, Sainctavit, Philippe, additional, Guihéry, Nathalie, additional, Mallah, Talal, additional, Cabaret, Delphine, additional, Gouéré, Diane, additional, Baudelet, François, additional, Nataf, Lucie, additional, Wilhelm, Fabrice, additional, Guillou, François, additional, Rogalev, Andrei, additional, Suaud, Nicolas, additional, Brooker, Sally, additional, and Juhin, Amélie, additional

Published
2022
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25. Strain-engineering of magnetic anisotropy in Co x Ni 1 − x − SrTiO 3 / SrTiO 3 (001) vertically assembled nanocomposites

Author

Weng, Xiaorong, Hennes, Marcel, Juhin, Amélie, Sainctavit, Philippe, Gobaut, Benoit, Otero, Edwige, Choueikani, Fadi, Ohresser, Philippe, Tran, Thomas, Hrabovsky, David, Demaille, Dominique, Zheng, Yunlin, Vidal, Franck, Croissance et propriétés de systèmes hybrides en couches minces (INSP-E8), Institut des Nanosciences de Paris (INSP), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Minéralogie et magnétisme de basses dimensionnalités [IMPMC] (IMPMC_MIMABADI), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Sorbonne université - Faculté des Sciences et Ingénierie (SU FSI), and Sorbonne Université (SU)

Subjects
[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci]
Abstract

International audience; Ultrathin CoxNi1−x alloy nanowires vertically embedded in SrTiO3 /SrTiO3 (001) thin films were grown using a self-assembly approach based on sequential pulsed laser deposition. Due to vertical epitaxial coupling of the metallic and oxide phases, a large average tensile strain of up to 4% arises within the nanowires, which is evidenced using a combination of x-ray diffraction and transmission electron microscopy. Macroscopic magnetometry experiments are used to demonstrate that this huge deformation allows to enhance the uniaxial anisotropy of the nanowires, leading to saturation field in excess of 1 T in the hard direction, large coercive field at low temperature along the easy axis, and to a blocking temperature exceeding 600 K in the case of nanowires with a diameter of 5 nm and 78% Co content. These data are complemented with angular dependent x-ray magnetic circular dichroism measurements at the Co and Ni L2,3-edges. The value of the magnetic moment was extracted from these measurements by applying sum rules and the anisotropy of the orbital moment was investigated.

Published
2022
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26. A TbPc 2 sub-monolayer deposit on a titanium dioxide ultrathin film: magnetic, morphological, and chemical insights

Author

Sorrentino, Andrea Luigi, Cimatti, Irene, Serrano, Giulia, Poggini, Lorenzo, Cortigiani, Brunetto, Malavolti, Luigi, Otero, Edwige, Sainctavit, Philippe, Mannini, Matteo, Sessoli, Roberta, Caneschi, Andrea, Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Dipartimento di Chimica 'U. Schiff' and UdR INSTM, Department of Chemistry 'Ugo Schiff', Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), National Interuniversity Consortium of Materials Science and Technology (INSTM ), Laboratory of Molecular Magnetism, and INSTM di Firenze

Subjects
[CHIM.COOR]Chemical Sciences/Coordination chemistry, [PHYS.COND.CM-SCE]Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el]
Abstract

International audience; Thin inorganic films ( i.e. , metal oxides) are often used as decoupling layers to optimize the interactions between the molecular magnetic layers and metallic surfaces.

Published
2021
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27. Magnetic molecules as sensors of topological hysteresis of superconductors

Author

Serrano, Giulia, primary, Poggini, Lorenzo, additional, Cucinotta, Giuseppe, additional, Sorrentino, Andrea, additional, Giaconi, Niccolò, additional, Cortigiani, Brunetto, additional, Longo, Danilo, additional, Otero, Edwige, additional, Sainctavit, Philippe, additional, Caneschi, Andrea, additional, Mannini, Matteo, additional, and Sessoli, Roberta, additional

Published
2022
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28. Metal-to-metal electron transfer in a cyanido-bridged {Fe2Co2} square complex followed by X-ray diffraction and absorption techniques

Author

Mathonière, Corine, primary, Mitcov, Dmitri, additional, Koumousi, Evangelia, additional, Amorin-Rosario, Daniel, additional, Dechambenoit, Pierre, additional, Fatima Jafri, Sadaf, additional, Sainctavit, Philippe, additional, Cartier dit Moulin, Christophe, additional, Toupet, Loic, additional, Trzop, Elzbieta, additional, Collet, Eric, additional, Arrio, Marie-Anne, additional, Rogalev, Andrei, additional, Wilhelm, Fabrice, additional, and Clérac, Rodolphe, additional

Published
2022
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29. Engineering Chemisorption of Fe 4 Single‐Molecule Magnets on Gold

Author

Poggini, Lorenzo, primary, Tancini, Erik, additional, Danieli, Chiara, additional, Sorrentino, Andrea Luigi, additional, Serrano, Giulia, additional, Lunghi, Alessandro, additional, Malavolti, Luigi, additional, Cucinotta, Giuseppe, additional, Barra, Anne‐Laure, additional, Juhin, Amélie, additional, Arrio, Marie‐Anne, additional, Li, Weibin, additional, Otero, Edwige, additional, Ohresser, Philippe, additional, Joly, Loïc, additional, Kappler, Jean Paul, additional, Totti, Federico, additional, Sainctavit, Philippe, additional, Caneschi, Andrea, additional, Sessoli, Roberta, additional, Cornia, Andrea, additional, and Mannini, Matteo, additional

Published
2021
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30. Metal-to-metal electron transfer in a cyanido-bridged {Fe2Co2} square complex followed by X-ray diffraction and absorption techniques.

Author

Mathoniεave;re, Corine, Mitcov, Dmitri, Koumousi, Evangelia, Amorin-Rosario, Daniel, Dechambenoit, Pierre, Fatima Jafri, Sadaf, Sainctavit, Philippe, Cartier dit Moulin, Christophe, Toupet, Loic, Trzop, Elzbieta, Collet, Eric, Arrio, Marie-Anne, Rogalev, Andrei, Wilhelm, Fabrice, and Clérac, Rodolphe

Subjects
CHARGE exchange, X-ray absorption, X-ray diffraction, X-ray spectroscopy, X-ray scattering
Abstract

The switching properties of a cyanido-bridged Fe/Co square molecule were investigated by single-crystal X-ray diffraction and X-ray absorption spectroscopy at both Fe and Co K-edges. Combining these two techniques, a complete picture of the thermal-, light- and X-ray-induced metal-to-metal electron transfer is obtained, illustrating the concerted role played by the Fe and Co sites. [ABSTRACT FROM AUTHOR]

Published
2022
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32. Electronic structure and local environment of substitutional [V.sup.3+] in grossular garnet [Ca.sub.3][Al.sub.2][(Si[O.sub.4]).sub.3]: K-edge X-ray absorption spectroscopy and first-principles modeling

Author

Bordage, Amelie, Brouder, Christian, Balan, Etienne, Cabaret, Delphine, Juhin, Amelie, Arrio, Marie-Anne, Sainctavit, Philippe, Calas, Georges, and Glatzel, Pieter

Subjects
Density functionals -- Research, Garnet -- Spectra, X-ray spectroscopy -- Methods, Crystals -- Structure, Crystals -- Observations, Earth sciences
Abstract

The V K-edge spectrum of a V-bearing grossular garnet (tsavorite) single crystal has been measured by high-energy resolution fluorescence detected X-ray absorption spectroscopy (HERFD-XAS). First-principles calculations based on the density functional theory (DFT) reproduce the experimental spectra well, including the angular dependence of the pre-edge. The latter arises from pure electric quadrupole transitions since vanadium is incorporated in a centrosymmetric site, which inhibits the electric dipole transitions. An interpretation of the spectral features is given using a monoelectronic description of the transitions involved in the X-ray absorption process. The assignment of experimental pre-edge peaks in terms of 1s-3d transitions makes it possible to determine the magnitude of the 3d-splitting, which is similar to the 10 Dq crystal-field value determined from optical absorption spectroscopy. DFT calculations also indicate a full structural relaxation around [V.sup.3+] substituting [Al.sup.3+] in the garnet structure. The angular dependence only causes weak variations of the pre-edge intensity, which supports the use of V-bearing grossular garnet as a reference compound for octahedral [V.sup.3+]. Keywords: Vanadium, garnet, HERFD-XAS, DFT calculations, K pre-edge, angular dependence, structural relaxation, crystal-field splitting DOI: 10.2138/am.2010.3432

Published
2010

33. Engineering Chemisorption of Fe 4 Single‐Molecule Magnets on Gold

Author

Totti Federico, Ohresser Philippe, Poggini Lorenzo, Erik Tancini, Barra Anne-Laure, Sessoli Roberta, Chiara Danieli, Caneschi Andrea, Jean Paul Kappler, Cucinotta Giuseppe, Li Weibin, Mannini Matteo, Arrio Marie-Anne, Malavolti Luigi, Lunghi Alessandro, Joly Loïc, Serrano Giulia, Andrea Cornia, Juhin Amélie, Otero Edwige, Sainctavit Philippe, Andrea Sorrentino, Istituto di Chimica dei Composti Organometallici (ICCOM), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Università degli Studi di Firenze = University of Florence (UniFI), Università degli Studi di Modena e Reggio Emilia = University of Modena and Reggio Emilia (UNIMORE), Laboratoire national des champs magnétiques intenses - Grenoble (LNCMI-G ), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Consiglio Nazionale delle Ricerche (CNR), Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Università degli Studi di Modena e Reggio Emilia (UNIMORE), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), and Gestionnaire, Hal Sorbonne Université

Subjects
Materials science, single-molecule magnets, self-assembled monolayers, nanomagnetism, synchrotron radiation, spintronics, ab initio molecular dynamics, DFT, Synchrotron radiation, 02 engineering and technology, ab initio molecular dynamics, DFT, nanomagnetism, self-assembled monolayers, single-molecule magnets, spintronics, synchrotron radiation, 010402 general chemistry, 01 natural sciences, Ab initio molecular dynamics, Condensed Matter::Materials Science, Molecule, [CHIM.MATE] Chemical Sciences/Material chemistry, Spintronics, Mechanical Engineering, Self-assembled monolayer, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, equipment and supplies, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, [CHIM.THEO] Chemical Sciences/Theoretical and/or physical chemistry, Mechanics of Materials, Chemical physics, Chemisorption, Magnet, 0210 nano-technology, human activities
Abstract

International audience; Gaining control over the grafting geometry is critically important for any application of surface-supported single-molecule magnets (SMMs) in data storage, spintronics, and quantum information science. Here, tetrairon(III) SMMs with a propeller-like structure are functionalized with thioacetyl-terminated alkyl chains to promote chemisorption on gold surfaces from solution and to evaluate differences in adsorption geometry and magnetic properties as a function of chain length. The prepared monolayers are investigated using X-ray absorption techniques with linearly and circularly polarized light to extract geometrical and magnetic information, respectively. All derivatives remain intact and form partially oriented monolayers on the gold surface. A ligand-field analysis of the observed X-ray natural linear dichroism shows that the threefold molecular axis is invariably biased toward the surface normal, in agreement with ab initio calculations. This preferential orientation is most pronounced in monolayers of the shortest-chain derivative, which are further studied with an ultralow temperature X-ray magnetic circular dichroism setup operating down to 350 mK. The isothermal field sweeps with the magnetic field at normal incidence show an open hysteresis loop below 1 K, while measurements at different incidence angles prove the magnetic anisotropy of the monolayers.

Published
2021
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34. Thermal Bistability of an Ultrathin Film of Iron(II) Spin-Crossover Molecules Directly Adsorbed on a Metal Surface

Author

Kelai, Massine, primary, Repain, Vincent, additional, Tauzin, Arthur, additional, Li, Weibin, additional, Girard, Yann, additional, Lagoute, Jérôme, additional, Rousset, Sylvie, additional, Otero, Edwige, additional, Sainctavit, Philippe, additional, Arrio, Marie-Anne, additional, Boillot, Marie-Laure, additional, Mallah, Talal, additional, Enachescu, Cristian, additional, and Bellec, Amandine, additional

Published
2021
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35. Biogenic vs. abiogenic magnetite nanoparticles: a XMCD study

Author

Carvallo, Claire, Sainctavit, Philippe, Arrio, Marie-Anne, Menguy, Nicolas, Wang, Yuheng, Ona-Nguema, Georges, and Brice-Profeta, Sandrine

Subjects
Magnetite -- Properties, Nanoparticles -- Magnetic properties, Biomineralization -- Evaluation, Shewanella -- Natural history, Circular dichroism -- Testing, Earth sciences
Abstract

X-ray magnetic circular dichroism (XMCD) experiments were carried out to compare the [Fe.sup.2+] [Fe.sup.3+] ratio in nanomagnetite chemically produced from lepidocrocite and nanomagnetite biogenically produced by the Fe-reducing bacterium Shewanella putrefaciens. Together with TEM imaging, these measurements showed that the biotic magnetite nanoparticles were of excellent quality, with small size dispersion and high crystallinity. From the XMCD measurements, it could be shown that the biogenic nanomagnetite contained a higher amount of [Fe.sup.2+] than the abiogenic nanomagnetite. Keywords: Nanomagnetite, XMCD, Shewanella putrefaciens, biomineralization

Published
2008

38. XMCD for monitoring exchange interactions. The role of the Gd 4f 5d orbitals in metal-nitronyl nitroxide magnetic chains

Author

Champion, Guillaume, Lalioti, Nikolia, Arrio, Marie-Anne, Sainctavit, Philippe, Baudelet, Francois, Verdaguer, Michel, and Moulin, Christopher Cartier dit

Subjects
Radicals (Chemistry) -- Usage, Nitro compounds -- Magnetic properties, Nitro compounds -- Research, Chemistry
Abstract

The X-ray magnetic circular dichronism (XMCD) study at the Gd M(sub 4,5-) and L(sub 2,3-) edges of two linear magnetic chains involving Gd(III) cations bridged by nitronyl nitroxide radicals is reported. The spectroscopy directly probes the magnetic moments of the 4f and 5d orbitals of the gadolinium ions.

Published
2003

40. A TbPc2 sub-monolayer deposit on a titanium dioxide ultrathin film: magnetic, morphological, and chemical insights

Author

Sorrentino, Andrea Luigi, primary, Cimatti, Irene, additional, Serrano, Giulia, additional, Poggini, Lorenzo, additional, Cortigiani, Brunetto, additional, Malavolti, Luigi, additional, Otero, Edwige, additional, Sainctavit, Philippe, additional, Mannini, Matteo, additional, Sessoli, Roberta, additional, and Caneschi, Andrea, additional

Published
2021
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41. Robust magnetic anisotropy of a monolayer of hexacoordinate Fe(ii) complexes assembled on Cu(111)

Author

Kelai, Massine, primary, Cahier, Benjamin, additional, Atanasov, Mihail, additional, Neese, Frank, additional, Tong, Yongfeng, additional, Zhang, Luqiong, additional, Bellec, Amandine, additional, Iasco, Olga, additional, Rivière, Eric, additional, Guillot, Régis, additional, Chacon, Cyril, additional, Girard, Yann, additional, Lagoute, Jérôme, additional, Rousset, Sylvie, additional, Repain, Vincent, additional, Otero, Edwige, additional, Arrio, Marie-Anne, additional, Sainctavit, Philippe, additional, Barra, Anne-Laure, additional, Boillot, Marie-Laure, additional, and Mallah, Talal, additional

Published
2021
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44. Ultrasmall CoFe2O4 magnetic nanoparticles in ferrofluids, influence of the synthesis on the magnetic anisotropies

Author

Daffé, Niéli, Gavrilov, Véronica, Neveu, Sophie, Choueikani, Fadi, Arrio, Marie-Anne, Juhin, Amélie, Ohresser, Philippe, Sainctavit, Philippe, Dupuis, Vincent, Sainctavit, Philippe, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Université (SU), Dispositifs et Instrumentation en Optoélectronique et micro-ondes (DIOM), Université Jean Monnet - Saint-Étienne (UJM), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), 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), and Université Jean Monnet [Saint-Étienne] (UJM)

Subjects
[CHIM.INOR] Chemical Sciences/Inorganic chemistry, XMCD, CoFe2O4, nanoparticles Corresponding Author Niéli Daffé, [PHYS.COND.CM-SCE] Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el], spinel ferrite, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, [PHYS.COND.CM-SCE]Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el], anisotropies
Abstract

International audience; The magnetic properties of cobalt ferrites nanoparticles prepared using three different processes (thermal decomposition, polyol and co-precipitation synthesis routes) are investigated by X-ray Absorption Spectroscopy and X-ray Magnetic Circular Dichroism. The repartition of cobalt and iron ions amongst the various sites of the spinel structure is determined and correlated with their magnetic properties. The study reports on the influence of the synthesis method on the crystallographic order within a nanoparticle, and hence, on the magnetic anisotropy.

Published
2019

45. Anomalous Light‐Induced Spin‐State Switching for Iron(II) Spin‐Crossover Molecules in Direct Contact with Metal Surfaces

Author

Zhang, Luqiong, primary, Tong, Yongfeng, additional, Kelai, Massine, additional, Bellec, Amandine, additional, Lagoute, Jérôme, additional, Chacon, Cyril, additional, Girard, Yann, additional, Rousset, Sylvie, additional, Boillot, Marie‐Laure, additional, Rivière, Eric, additional, Mallah, Talal, additional, Otero, Edwige, additional, Arrio, Marie‐Anne, additional, Sainctavit, Philippe, additional, and Repain, Vincent, additional

Published
2020
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46. Enhancement of the Magnetic Coupling in Exfoliated CrCl 3 Crystals Observed by Low‐Temperature Magnetic Force Microscopy and X‐ray Magnetic Circular Dichroism

Author

Serri, Michele, primary, Cucinotta, Giuseppe, additional, Poggini, Lorenzo, additional, Serrano, Giulia, additional, Sainctavit, Philippe, additional, Strychalska‐Nowak, Judyta, additional, Politano, Antonio, additional, Bonaccorso, Francesco, additional, Caneschi, Andrea, additional, Cava, Robert J., additional, Sessoli, Roberta, additional, Ottaviano, Luca, additional, Klimczuk, Tomasz, additional, Pellegrini, Vittorio, additional, and Mannini, Matteo, additional

Published
2020
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47. Photoinduced ferrimagnetic systems in Prussian blue analogues C(super I)(sub x)CO4(Fe(CN)6)(sub y) (C(super I) = alkali cation). 2. X-ray absorption spectroscopy of the metastable state

Author

Cartier dit Moulin, Christophe, Villain, Francoise, Bleuzen, Anne, Arrio, Marie-Anne, Sainctavit, Philippe, Lomenech, Claire, Escax, Virginie, Baudelet, Francois, Dartyge, Elizabeth, Gallet, Jean-Jacques, and Verdaguer, Michel

Subjects
Cobalt -- Magnetic properties, Complex compounds -- Research, Extended X-ray absorption fine structure -- Observations, Chemistry
Abstract

An analysis of the structure of a synthesized Prussian blue analogue using x-ray absorption spectroscopy is discussed. The results which increase our knowledge of the photoinduced electron transfer are presented.

Published
2000

49. Rapid discrimination of crystal handedness by XNCD mapping

Author

Cortijo, Miguel, Valentín-Pérez, Ángela, Rogalev, Andrei, Wilhelm, Fabrice, Sainctavit, Philippe, Rosa, Patrick, Hillard, Elizabeth Anne, 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), Centre de Recherche Paul Pascal (CRPP), Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and This work was supported by the CNRS, the University of Bordeaux, the Conseil Régional de la Nouvelle Aquitaine, the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 706556 CHIMMM (Postdoctoral fellowship for MC), the French Ministry of Higher Education, Research and Innovation (PhD bursary for AVP), and the European Synchrotron Radiation Facility (beamtime CH-5531). The authors thank R. Clérac for useful discussions.

Subjects
X-ray optical activity, [CHIM.CRIS]Chemical Sciences/Cristallography, Conglomerate crystallization, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Chirality, X-ray absorption, Coordination chemistry
Abstract

International audience; An original method for determining the handedness of individual non‐centrosymmetric crystals in a mixture using a tightly‐focused, circularly polarized X‐ray beam is presented. The X‐ray natural circular dichroism (XNCD) spectra recorded at the metal K‐edge on selected crystals of [Δ‐M(en)3](NO3)2 and [Λ‐M(en)3](NO3)2 (M=CoII, NiII) show extrema at the metal pre‐edge (7712 eV for Co, 8335 eV for Ni). A mapping of a collection of some 220 crystals was performed at the respective energies by using left and right circular polarizations. The difference in absorption for the two polarizations, being either negative or positive, directly yielded the handedness of the crystal volume probed by the beam. By using this technique, it was found that the addition of l‐ascorbic acid during the synthesis of [Co(en)3](NO3)2 resulted in an enantiomeric enrichment of the Λ‐isomer of 67±13 %, whereas the Ni analogue was similarly, but conversely, enriched in the Δ‐isomer (65±22 %).

Published
2020
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