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1. Transport and Thermoelectric Coefficients of the Co9S8 Metal: A Comparison with the Spin Polarized CoS2

Author

Antoine Maignan, Sylvie Hébert, David Berthebaud, Tristan Barbier, Oleg I. Lebedev, Valerie Pralong, 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), Université de Caen Normandie (UNICAEN), 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), Laboratory for Innovative Key Materials and Structures (LINK), Saint-Gobain-National Institute of Materials Science-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences et Techniques de la Réadaptation [Lyon] (ISTR), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon

Subjects
Diffraction, Materials science, Spark plasma sintering, 02 engineering and technology, Sulfides, 010402 general chemistry, Quantum mechanics, 01 natural sciences, Metal, Magnetic properties, Thermoelectric effect, [CHIM]Chemical Sciences, Ceramic, Physical and Theoretical Chemistry, Spin (physics), ComputingMilieux_MISCELLANEOUS, [PHYS]Physics [physics], Condensed matter physics, Lattices, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, General Energy, Thermal conductivity, Transmission electron microscopy, visual_art, visual_art.visual_art_medium, 0210 nano-technology, Powder diffraction
Abstract

International audience; A Co9S8 dense ceramic sintered by spark plasma sintering has been characterized by X-ray powder diffraction and transmission electron microscopy (diffraction and high resolution). This allowed magnetic, electronic, and thermal transport measurements to be made for a cubic (a = 9.927(2)Å) Co9S8 sample free of impurities and structural defects. The magnetic susceptibility and magnetic field dependence of the magnetization point toward an antiferromagnetic state, whereas the four-probe resistivity reveals a very metallic behavior with ρ300 K = 80 μΩ.cm described by a classical electron phonon model. When compared to CoS2, even if Co9S8 exhibits lower ρ values associated with the lack of ferromagnetic fluctuations existing in the former, the Co9S8 thermoelectric power factor, negative as in CoS2, is smaller, nonetheless leading to a power factor (PF) reaching PF ≈ 0.5 mW m–1 K–2 at 300 K. In Co9S8, with its low ρ going with a very high electronic part of the thermal conductivity κ, the lattice part of κ is smaller than that of CoS2 (∼2 W m–1 K–1 for Co9S8 at 300 K) suggesting that the more complex structure of Co9S8, with two different types of CoSn polyhedra, plays an important role.

Published
2021
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2. Na 2 VO(HPO 4 ) 2 : an original phase solved by continuous 3D electron diffraction and powder X-ray diffraction

Author

V. Gopal, Valerie Pralong, O. Leynaud, M. Gnanavel, C. Lepoittevin, Tristan Barbier, A. Neveu, 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), Matériaux, Rayonnements, Structure (MRS), 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), X'Press (X'Press), and Normandie Université (NU)

Subjects
Diffraction, Materials science, Proton, Cathode material, Analytical chemistry, 02 engineering and technology, Crystal structure, 010402 general chemistry, 01 natural sciences, Ion, Inorganic Chemistry, Phase (matter), [CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM]Chemical Sciences, 3D Electron Diffraction, Na2VO(HPO4)2, exchange, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Electron diffraction, X-ray crystallography, Vanadium hydrogeno phosphate, Transmission Electron Microscopy, Orthorhombic crystal system, 0210 nano-technology, Na-ion battery
Abstract

International audience; The new phase Na 2 VO(HPO 4) 2 was synthesized by sodium/proton ion exchange between NaI and VO (H 2 PO 4) 2 in hexanol. The exchange of two protons by two sodium ions causes a structural reorganization leading to a new original phase. The crystal structure was solved by continuous 3D Electron Diffraction, consisting of recording a video in diffraction mode during the continuous sample holder rotation in order to acquire a complete dataset in a shortest time in order to avoid the deterioration of this electron beam sensitive material. The individual Electron Diffraction patterns were extracted from the video, processed by conventional electron diffraction crystallography programs (PETS, JANA2006) and the resulting structural model calculated by the charge flipping algorithm was refined from powder X-ray diffraction data. This material crystallizes in an orthorhombic unit cell in the Iba2 (45) space group, with the cell parameters a = 13.86852(19), b = 13.7985(2), c = 7.47677(9). Electrochemical studies show that up to 0.66 Na f.u. −1 could be removed from Na 2 VO(HPO 4) 2 .

Published
2021
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3. Tetrahedrites Synthesized via Scalable Mechanochemical Process and Spark Plasma Sintering

Author

Tristan Barbier, Matej Baláž, Mária Kaňuchová, Oleksandr Dobrozhan, Peter Baláž, Emmanuel Guilmeau, Marcela Achimovičová, Nina Daneu, Jaroslav Briančin, Michal Hegedüs, 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), Slovak Academy of Sciences (SAS), Université de Caen Normandie (UNICAEN), 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), Jozef Stefan Institute [Ljubljana] (IJS), Sumy State University, Synthon, and Technical University of Kosice

Subjects
Mechanochemical, Materials science, Tetrahedrite, Sulfide, Composite number, Spark plasma sintering, SPS, 02 engineering and technology, engineering.material, 01 natural sciences, Thermal conductivity, 0103 physical sciences, Thermoelectric effect, Materials Chemistry, 010302 applied physics, Thermoelectric, [CHIM.MATE]Chemical Sciences/Material chemistry, Covellite, 021001 nanoscience & nanotechnology, Thermoelectric materials, Chemical engineering, visual_art, Ceramics and Composites, visual_art.visual_art_medium, engineering, 0210 nano-technology, Ternary operation
Abstract

International audience; In this study, we demonstrate the use of elemental precursors (Cu,Sb,S) to synthesize tetrahedrite Cu12Sb4S13 using an industrial eccentric vibratory mill. Mechanochemical synthesis of tetrahedrite leads to the formation of covellite (CuS), skinnerite (Cu3SbS3) or famatinite (Cu3SbS4) in dependence on milling time. However, the composite product can be modified in favour of prevailing tetrahedrite when Spark Plasma Sintering (SPS) treatment is applied after milling. The as-synthesized and sintered products are composed of polydisperse nanosized particles with dimensions up to 250 nm. The thermoelectric measurements reveal a maximum value of figure-of-merit ZT = 0.67 @ 700 K, as a consequence of a relatively high power factor (1.07 mW m−1 K−2) and a low thermal conductivity (1.12 W m−1 K−1). The obtained zT values of products prepared in an industrial mill are comparable to the ones reported for compounds synthesized using laboratory mills. The synthesis of ternary and quaternary sulphides by a scalable and industrializable milling process represents a prospective route for mass production of thermoelectric materials.

Published
2020
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4. Thermal deformation effects on thermoelectric properties for Bi0.82Sb0.18 alloys

Author

Tomonari Takeuchi, Tristan Barbier, Emmanuel Combe, Ryoji Funahashi, and Kunio Yubuta

Subjects
010302 applied physics, Materials science, Phonon scattering, Mechanical Engineering, Metallurgy, Alloy, Metals and Alloys, Sintering, 02 engineering and technology, engineering.material, 021001 nanoscience & nanotechnology, Thermoelectric materials, 01 natural sciences, Thermal conductivity, Mechanics of Materials, Electrical resistivity and conductivity, 0103 physical sciences, Thermoelectric effect, Materials Chemistry, engineering, Electric current, Composite material, 0210 nano-technology
Abstract

Bi0.82Sb0.18 alloy bulk materials have been prepared by mechanical alloying followed by a pulsed electric current sintering (PECS) technique. The sintered Bi0.82Sb0.18 pellets were deformed in the direction perpendicular to applied pressure by a second PECS treatment. Significant decreases of both electrical resistivity and lattice part of the thermal conductivity have been obtained for the deformed alloys. Improved electrical transport properties in deformed Bi0.82Sb0.18 alloys are attributed to the improvement of bulk density. On the other hand, the lattice part of thermal conductivity is decreased by the deforming treatment. Dislocations and twin domains are formed by the applied deformation. Furthermore the density of the defects is increased with increasing deformation temperature. The lower lattice thermal conductivity is observed in the higher density of defects, which can be one of the reasons for phonon scattering sites. The alloy prepared with deformation treatment at 493 K exhibits a thermoelectric figure of merit ZT of 0.31 at 200 K, improved by a factor about 1.5 by comparison with Bi0.82Sb0.18 alloy prepared by a conventional single PECS heat treatment.

Published
2017
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5. The crucial role of selenium for sulphur substitution in the structural transitions and thermoelectric properties of Cu5FeS4 bornite

Author

Vivian Nassif, Bernard Raveau, Tristan Barbier, V. Pavan Kumar, Emmanuel Guilmeau, Pierric Lemoine, 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), 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), CRG et Grands Instruments (CRG ), Institut Néel (NEEL), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), ANR-10-LABX-09-01, Agence Nationale de la Recherche, Université de Caen Normandie (UNICAEN), 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), 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), CRG & Grands instruments (NEEL - CRG), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-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)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Chemistry, Analytical chemistry, Spark plasma sintering, 02 engineering and technology, Atmospheric temperature range, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Inorganic Chemistry, Metal, Crystallography, Thermal conductivity, Effective mass (solid-state physics), Electrical resistivity and conductivity, visual_art, Thermoelectric effect, visual_art.visual_art_medium, [CHIM]Chemical Sciences, Orthorhombic crystal system, 0210 nano-technology
Abstract

Bornite Cu5FeS4-xSex (0 ≤ x ≤ 0.6) compounds have been synthesized, using mechanical alloying, combined with spark plasma sintering (SPS). High temperature in situ neutron powder diffraction data collected on pristine Cu5FeS4 from room temperature up to 673 K show that SPS enables the stabilization of the intermediate cubic (IC) semi-ordered form (Fm3[combining macron]m, aIC ∼ 10.98 A) at the expense of the ordered orthorhombic form (Pbca, aO ∼ 10.95 A, bO ∼ 21.86 A, cO ∼ 10.95 A) in the 300-475 K temperature range, whereas above 475 K the IC form coexists with the high temperature cubic (C) form (Fm3[combining macron]m, aC ∼ 5.50 A). The ability of Se for S substitution to induce disorder and consequently to enhance the IC phase formation is also emphasized. This disordering effect is explained by the high quenching efficiency of the SPS method compared to conventional heating. The existence of topotactic phase transformations, as well as Se for S substitution is shown to have a significant effect on the transport properties. As expected, electrical transport properties indicate a change towards a more metallic behaviour with increasing Se content. The electrical resistivity reduces from ∼21.4 mΩ cm for the pristine Cu5FeS4 to ∼3.95 mΩ cm for Cu5FeS3.4Se0.6 at room temperature. A maximum power factor of 4.9 × 10-4 W m-1 K-2 is attained at 540 K for x = 0.4 composition. The influence of selenium substitution on the carrier effective mass and mobility is discussed based on single parabolic band approximation. Furthermore, a detailed investigation of the thermal conductivity by this isovalent anion substitution reveals a significant reduction of the lattice thermal conductivity due to the alloying effect. Finally, the important role of structural transitions in the thermoelectric properties is addressed. A maximum ZT of 0.5 is attained at 540 K for Cu5FeS3.8Se0.2 composition.

Published
2017
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6. Structural and thermoelectric properties of n-type isocubanite CuFe2S3

Author

Antoine Maignan, David Berthebaud, Raymond Frésard, Emmanuel Guilmeau, Volker Eyert, Tristan Barbier, Oleg I. Lebedev, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Université de Caen Normandie (UNICAEN), Normandie Université (NU), French Agence Nationale de la Recherche (ANR) [ANR-10-LABX-09-01], LabEx EMC3, European Union, 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), Université de Caen Normandie (UNICAEN), 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), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Mineralogy, 02 engineering and technology, engineering.material, 010402 general chemistry, 01 natural sciences, Inorganic Chemistry, Electrical resistivity and conductivity, Thermoelectric effect, [CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM]Chemical Sciences, Antiferromagnetism, Pyrrhotite, Condensed matter physics, Rietveld refinement, Chalcopyrite, Cubanite, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, visual_art, engineering, visual_art.visual_art_medium, Orthorhombic crystal system, 0210 nano-technology
Abstract

International audience; An effective strategy to enhance thermoelectric performance consists of scattering phonons by point defects, such as the ones intrinsic to the n-type isocubanite CuFe2S3. In this structure, the TEM evidences a random distribution of vacancies, and copper and iron ions of the 4c and 4d sites naturally reduce the phonon lifetime. Furthermore, orthorhombic and cubic cubanite are usually found in their natural states intimately intergrown with other sulfides such as chalcopyrite (CuFeS2) and pyrrhotite (Fe7S8). We performed comprehensive studies of Rietveld analysis of X-ray diffraction, transmission electron microscopy, and thermoelectric transport measurements of the n-type isocubanite CuFe2S3, and we obtained a maximum ZT value of 0.14 at 700 K in this environmentally friendly compound. Our electronic structure calculations support the fact that chalcopyrite CuFeS2 is an antiferromagnetic insulator, together with a higher degree of covalency of sulfide compared to oxides. The weak temperature dependence of the resistivity points towards strong disorder in the 4c and 4d sites of the isocubanite.

Published
2017
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7. Thermoelectric properties, metal-insulator transition, and magnetism: Revisiting the Ni1−xCuxS2 system

Author

Tristan Barbier, Ramzy Daou, Emmanuel Guilmeau, Antoine Maignan, Sylvie Hébert, David Berthebaud, and Oleg I. Lebedev

Subjects
Materials science, Physics and Astronomy (miscellaneous), Magnetism, Charge (physics), 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Paramagnetism, Crystallography, Charge ordering, 0103 physical sciences, Thermoelectric effect, Antiferromagnetism, General Materials Science, Metal–insulator transition, 010306 general physics, 0210 nano-technology, Ground state
Abstract

The $\mathrm{N}{\mathrm{i}}_{1\ensuremath{-}x}\mathrm{C}{\mathrm{u}}_{x}{\mathrm{S}}_{2}$ pyrite ($x\ensuremath{\le}0.07$) is a model material where the impact of electron filling on a half-filled ${e}_{\mathrm{g}}$ band system can be separated from changes in the bandwidth, since the unit cell volume does not change with $x$. This contrasts with the $\mathrm{Ni}{\mathrm{S}}_{2\ensuremath{-}x}\mathrm{S}{\mathrm{e}}_{x}$ system where the size difference between ${\mathrm{S}}^{2\ensuremath{-}}$ and $\mathrm{S}{\mathrm{e}}^{2\ensuremath{-}}$ makes the bandwidth vary at constant band filling. Our magnetic measurements show that there exists a clear relation between the presence of the antiferromagnetic phase developing below ${T}_{\mathrm{N}2}=29.75\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ and charge localization. With the addition of Cu in $\mathrm{N}{\mathrm{i}}_{1\ensuremath{-}x}\mathrm{C}{\mathrm{u}}_{x}{\mathrm{S}}_{2}$, the ground state evolves towards a metallic paramagnetic state. These findings are discussed with the scenario based on charge ordering at low temperature in the charge transfer insulator $\mathrm{Ni}{\mathrm{S}}_{2}$ pyrite, and also considering possible conducting surface states at low temperatures. At 300 K, the thermal conductivity decreases by 2.5 as $x$ increases from 0.00 to 0.07, even though the latter is much more electrically conductive than the former. This considerably extends the range of values for the thermal conductivity of the $\mathrm{M}{\mathrm{S}}_{2}$ pyrites, from the largest in $\mathrm{Fe}{\mathrm{S}}_{2}$ to the lowest in the present $\mathrm{N}{\mathrm{i}}_{1\ensuremath{-}x}\mathrm{C}{\mathrm{u}}_{x}{\mathrm{S}}_{2}$ samples.

Published
2019
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8. XBi 4 S 7 (X = Mn, Fe): New Cost‐Efficient Layered n ‐Type Thermoelectric Sulfides with Ultralow Thermal Conductivity

Author

Héloïse Willeman, Pierric Lemoine, Erik Elkaim, Thierry Le Mercier, Carmelo Prestipino, Abdelhamid Bourhim, Florian Appert, Arthur Huguenot, Bernard Malaman, Régis Gautier, Jean Juraszek, Agathe Virfeu, Antoine Maignan, Rabih Al Rahal Al Orabi, Lauriane Pautrot-d'Alençon, Emmanuel Guilmeau, Tristan Barbier, Vivian Nassif, Jean-Baptiste Labégorre, 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), Solvay (France), Groupe de physique des matériaux (GPM), Centre National de la Recherche Scientifique (CNRS)-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)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), Institut Jean Lamour (IJL), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-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), CRG et Grands Instruments (CRG ), Institut Néel (NEEL), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Université de Caen Normandie (UNICAEN), 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), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-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)-Institut de Recherche sur les Matériaux Avancés (IRMA), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-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), CRG & Grands instruments (NEEL - CRG), and Central Michigan University (CMU)

Subjects
Materials science, Condensed matter physics, Phonon, sulfides, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, thermoelectric, DFT calculations, 01 natural sciences, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, Biomaterials, Thermal conductivity, Thermoelectric effect, Electrochemistry, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [CHIM]Chemical Sciences, thermal conductivity, 0210 nano-technology, phonon
Abstract

International audience; A new class of cost‐efficient n‐type thermoelectric sulfides with a layered structure is reported, namely MnBi4S7 and FeBi4S7. Theoretical calculations combined with synchrotron X‐ray/neutron diffraction analyses reveal the origin of their electronic and thermal properties. The complex low‐symmetry monoclinic crystal structure generates an electronic band structure with a mixture of heavy and light bands near the conduction band edge, as well as vibrational properties favorable for high thermoelectric performance. The low thermal conductivity can be attributed to the complex layered crystal structure and to the existence of the lone pair of electrons in Bi3+. This feature combined with the relatively high power factor lead to a figure of merit as high as 0.21 (700 K) in undoped MnBi4S7, making this material a promising n‐type candidate for low‐ and intermediate‐temperature thermoelectric applications.

Published
2019
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9. Structural Investigation and Indium Substitution in the Thermoelectric Mn2.7Cr0.3Si4Al2−x In x Series

Author

Yuzuru Miyazaki, Emmanuel Guilmeau, Masataka Kubouchi, Emmanuel Combe, Tristan Barbier, Tomonori Takeuchi, Ryoji Funahashi, Ryosuke O. Suzuki, 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), National Institute of Advanced Industrial Science and Technology (AIST), Tohoku University [Sendai], Hokkaido University [Sapporo, Japan], Université de Caen Normandie (UNICAEN), 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), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Diffraction, Materials science, Solid-state physics, chemistry.chemical_element, 02 engineering and technology, single crystals, 01 natural sciences, silicide compounds, 0103 physical sciences, Thermoelectric effect, [CHIM.CRIS]Chemical Sciences/Cristallography, Materials Chemistry, [CHIM]Chemical Sciences, Electrical and Electronic Engineering, 010302 applied physics, Thermoelectric, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, Characterization (materials science), [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Crystallography, x-ray diffraction, chemistry, X-ray crystallography, Chemical stability, 0210 nano-technology, Indium, Solid solution
Abstract

International audience; Following the recent discovery of the promising Mn2.7Cr0.3Si4Al2 thermoelectric compound (having, e.g., automotive, industrial, and solar conversion applications), structural characterization by x-ray single-crystal diffraction analysis has been performed. This layered material is composed of two distinct crystallographic sites where both (Mn, Cr) and (Al, Si) are randomly distributed. The deduced crystallographic parameters were then confirmed by powder x-ray diffraction analysis through a temperature dependence of the phase stability, showing at the same time chemical stability up to 873 K. Taking into account the two distinct crystallographic sites highlighted, samples possessing two guest elements, one on each site, were then synthesized to improve the thermoelectric properties. A solid solution is found in the system Mn2.7Cr0.3Si4Al2−xInx with x varying from 0 to 0.2. Thus, double-substituted samples were studied by x-ray diffraction, electrical, and thermal measurements. The present paper describes and discusses the experimental results obtained. © 2016, The Minerals, Metals and Materials Society.

Published
2016
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10. Up-scaled synthesis process of sulphur-based thermoelectric materials

Author

Anthony V. Powell, Paz Vaqueiro, Pierric Lemoine, Emmanuel Guilmeau, Tristan Barbier, Margaux Gilmas, Mirva Eriksson, Gabin Guélou, Eric Hug, Sabrina Martinet, 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), Diamorph AB, University of Reading (UOR), Université de Caen Normandie (UNICAEN), 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), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Synthesis process, Materials science, General Chemical Engineering, Homogeneous materials, Thermoelectric equipment, Spark plasma sintering, chemistry.chemical_element, Sintering, Nanotechnology, Thermal transport properties, 02 engineering and technology, 010402 general chemistry, 7. Clean energy, 01 natural sciences, Thermoelectric performance, Nickel, Thermoelectric effect, [CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM]Chemical Sciences, Composite material, Elastic modulus, Thermo-Electric materials, Consolidation (soil), Elastic moduli, Thermoelectricity, [CHIM.MATE]Chemical Sciences/Material chemistry, General Chemistry, Hardness and elastic modulus, Thermoelectric devices, 021001 nanoscience & nanotechnology, Thermoelectric materials, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, chemistry, SCALE-UP, Consolidated materials, 0210 nano-technology
Abstract

International audience; The scale up of Spark Plasma Sintering (SPS) for the consolidation of large square monoliths (50 × 50 × 3 mm3) of thermoelectric materials is demonstrated and the properties of the fabricated samples compared with those from laboratory scale SPS. The SPS processing of n-type TiS2 and p-type Cu10.4Ni1.6Sb4S13 produces highly dense compacts of phase pure material. Electrical and thermal transport property measurements reveal that the thermoelectric performance of the consolidated n- and p-type materials is comparable with that of material processed using laboratory scale SPS, with ZT values that approach 0.75 and 0.35 at 700 K for Cu10.4Ni1.6Sb4S13 and TiS2, respectively. Mechanical properties of the consolidated materials show that large-scale SPS processing produces highly homogeneous materials with hardness and elastic moduli that deviate little from values obtained on materials processed on the laboratory scale. More generally, the process described in this paper is a promising way to produce high performance thermoelectric materials with square geometry, specifically required for thermoelectric device production. © The Royal Society of Chemistry 2016.

Published
2016
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11. CuFe

Author

Emmanuel, Anger, Antoine, Maignan, Tristan, Barbier, and Valerie, Pralong

Abstract

Electrochemical performances of the isocubanite CuFe

Published
2018

12. CuFe2S3 as electrode material for Li-ion batteries

Author

Emmanuel Anger, Tristan Barbier, Valerie Pralong, Antoine Maignan, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), 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), 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), and Normandie Université (NU)-Institut de Chimie du CNRS (INC)

Subjects
Electrode material, Materials science, General Chemical Engineering, Nanoparticle, chemistry.chemical_element, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Electrochemistry, 01 natural sciences, 7. Clean energy, Copper, 0104 chemical sciences, Ion, [SPI.MAT]Engineering Sciences [physics]/Materials, chemistry, Chemical engineering, 0210 nano-technology
Abstract

International audience; Electrochemical performances of the isocubanite CuFe2S3 tested as electrode material for Li-ion batteries have been investigated. A first discharge capacity of 860 mA h g(-1) shows a conversion process leading to Li2S, copper and iron nanoparticles. Interestingly, a reversible capacity of 560 mA h g(-1) at 1.5 V is demonstrated with good cyclability up to 30 cycles.

Published
2018
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13. Durability of Silicide-Based Thermoelectric Modules at High Temperatures in Air

Author

Ryoji Funahashi, Tomonari Takeuchi, Tristan Barbier, Ryosuke O. Suzuki, Yoko Matsumura, H. Takazawa, Emmanuel Combe, Atsushi Yamamoto, and Shigeru Katsuyama

Subjects
Materials science, Contact resistance, Composite number, Metallurgy, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, chemistry.chemical_compound, Thermoelectric generator, chemistry, Plating, Silicide, Electrode, Materials Chemistry, Electrical and Electronic Engineering, Composite material, Layer (electronics), Power density
Abstract

Thermoelectric modules consisting of n-type Mn2.7Cr0.3Si4Al2 and p-type MnSi1.75 legs have been fabricated by use of composite pastes of Ag with Pt or Pd. For the module prepared by Ni-B plating and with Ag paste, the specific power density reached 370 mW/cm2 at a heat-source temperature of 873 K. Ni-B plating 5 μm thick on the surfaces of the silicide legs reduced both the internal resistance and degradation of the power generated by silicide modules at temperatures up to 873 K in air. This is because of oxidation of Al diffusing into the n-type legs and reaching the Ag electrodes on both the hot and cold sides. Ni-B plating can suppress Al diffusion into n-type legs. However, cracking was observed parallel to the contact surface in the middle of the Ni-B plating layer on the p-type legs. It was also found that incorporating Pt or Pd into the Ag paste effectively suppressed degradation of the contact resistance between the silicide legs and the Ag electrodes.

Published
2015
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14. The Influence of Mobile Copper Ions on the Glass-Like Thermal Conductivity of Copper-Rich Tetrahedrites

Author

Paz Vaqueiro, Anthony V. Powell, Tristan Barbier, Emmanuel Guilmeau, Gabin Guélou, Ronald I. Smith, Andreas Kaltzoglou, ISIS Facility, STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC)-Science and Technology Facilities Council (STFC), 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), University of Reading (UOR), European Commission [315019], Université de Caen Normandie (UNICAEN), 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), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, General Chemical Engineering, Neutron diffraction, Analytical chemistry, Mineralogy, chemistry.chemical_element, 02 engineering and technology, engineering.material, 010402 general chemistry, 01 natural sciences, Thermal conductivity, Phase (matter), Thermoelectric effect, Materials Chemistry, [CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM]Chemical Sciences, Tetrahedrite, Lattices, General Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Thermoelectric materials, Copper, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Hysteresis, chemistry, Phase transitions, Temperature dependence, engineering, 0210 nano-technology
Abstract

International audience; Tetrahedrites are promising p-type thermoelectric materials for energy recovery. We present here the first investigation of the structure and thermoelectric properties of copper-rich tetrahedrites, Cu12+xSb4S13 (0 < x 0 consist of two tetrahedrite phases. In situ neutron diffraction data demonstrate that on heating, the two tetrahedrite phases coalesce into a single tetrahedrite phase at temperatures between 493 and 553 K and that this transition shows marked hysteresis on cooling. Our structural data indicate that copper ions become mobile above 393 K. Marked changes in the temperature dependence of the electrical and thermal transport properties of the copper-rich phases occur at the onset of copper mobility. Excess copper leads to a significant reduction in the total thermal conductivity, which for the nominal composition Cu14Sb4S13 reaches a value as low as 0.44 W m(-1) K-1 at room temperature, and to thermoelectric properties consistent with phonon liquid electron crystal (PLEC) behavior.

Published
2017
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15. Copper Hyper-Stoichiometry: The Key for the Optimization of Thermoelectric Properties in Stannoidite Cu8+xFe3–xSn2S12

Author

Gerard Le Caër, Pierric Lemoine, Ventrapati Pavan Kumar, Bernard Malaman, Bernard Raveau, Tristan Barbier, Emmanuel Guilmeau, Ramzy Daou, Vincent Caignaert, 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), Institut Jean Lamour (IJL), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), 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), 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), ANR-10-LABX-09-01, Agence Nationale de la Recherche, Université de Caen Normandie (UNICAEN), 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), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), 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), 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, Analytical chemistry, chemistry.chemical_element, Spark plasma sintering, 02 engineering and technology, Stannite, engineering.material, Sulfides, 010402 general chemistry, 01 natural sciences, Thermal conductivity, Seebeck coefficient, Thermoelectric effect, Physical and Theoretical Chemistry, Thermoelectrics, Metallurgy, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Copper, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, General Energy, chemistry, engineering, Thermoelectric materials, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0210 nano-technology, Tin, Stoichiometry
Abstract

International audience; A univalent copper hyper-stoichiometric stannoidite Cu8+xFe3–xSn2S12 with 0 ≤ x ≤ 0.5 has been synthesized using mechanical alloying followed by spark plasma sintering. The X-ray diffraction analysis combined with 57Fe and 119Sn Mössbauer investigations has allowed the charge distribution of the cationic species on the various sites to be established and suggests the possibility of a small tin deficiency. The transport properties show a remarkable crossover from a semiconducting to a metal-like behavior as the copper content increases from x = 0 to x = 0.5, whereas correlatively the Seebeck coefficient decreases moderately, with S values ranging from 310 to 100 μV/K. The thermal conductivity decreases as the temperature increases showing low values at high temperature, far below those reported in related stannite materials. The investigation of the thermoelectric properties shows that the ZT figure of merit is dramatically enhanced by the copper hyper-stoichiometry by a factor of 5 going from 0.07 for x = 0 to 0.35 for x = 0.5 at 630 K. This thermoelectric behavior is interpreted on the basis of a model involving the Cu–S framework as the conducting electronic network where the Fe2+/Fe3+ species play the role of hole reservoir.

Published
2017
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16. Decreased thermal conductivity in Bi2Sr2Co2Ox bulk materials prepared by partial melting

Author

Robert Freer, Feridoon Azough, Tristan Barbier, Ryoji Funahashi, and Emmanuel Combe

Subjects
010302 applied physics, Materials science, Phonon scattering, Mechanical Engineering, Partial melting, Oxide, Analytical chemistry, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Hot pressing, Microstructure, 01 natural sciences, chemistry.chemical_compound, Thermal conductivity, chemistry, Mechanics of Materials, 0103 physical sciences, Thermoelectric effect, General Materials Science, 0210 nano-technology, Porosity
Abstract

Bi2Sr2Co2Ox (BSC-222) bulk materials have been prepared in air by single hot pressing or partial melting followed by hot pressing. Thermal transport properties of as-prepared samples were compared with BSC-222 samples prepared by single partial melting. Samples prepared through hot pressing have a high bulk density and improved preferential grain orientation. Bulk density andpreferential grain orientation are significantly better in samples processed by partial melting followed by hot pressing. In samples prepared by partial melting, the presence of sub-micrometer-sized secondary phases Bi0.75Sr0.25Ox, Sr-based oxide, and CoO, is observed. The lattice contribution to the total thermal conductivity decreases significantly in partially melted BSC-222 samples. By using a classical phonon transport model, this result demonstrates that the decrease in lattice thermal conductivity in partially melted BSC-222 samples may be linked not only to porosity but also to the presence of defects, induced by partial melting process, which may play an important role in phononscattering.

Published
2016
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17. Thermoelectric properties of (BaCoO3-y)n BaCo8O11

Author

Tristan Barbier and Ryoji Funahashi

Subjects
chemistry.chemical_compound, Materials science, Thermal conductivity, chemistry, Electrical resistivity and conductivity, Seebeck coefficient, Electrical conduction, Thermoelectric effect, Oxide, Analytical chemistry, Figure of merit, Mineralogy, Composition (combinatorics)
Abstract

Thermoelectric properties of a homologous oxide system of (BaCoO3-y)nBaCo8O11 have been investigated at 373-973 K in air. All samples show positive Seebeck coefficient values, S, namely p-type character. Electrical resistivity, ρ of BaCoO3-y (n = ∞) decreases monotonically with increasing temperature. On the other hand, a transition in the electrical conduction is observed in the BaCo8O11 (n = 0), Ba2Co9O14 (n = 1), and Ba3Co10O17 (n = 2) around 500 K. Thermal conductivity looks to be decreased by the corner shared CoO6 structure. As the result of these properties, values of dimension-less figure of merit, ZT increase with increasing temperature and reach about 0.03 at 973 K for Ba2Co9O14. Cationic substitution at the Ba site has been carried out. The composition is Ba1.9M0.1Co9O14 (M: Na, Ca, Sr, and La). The substitution by Na is the most effective to enhance the S values at temperatures lower than 573 K. The values of power factor (= S2/ρ) for the samples substituted by Na and Sr are reach 0.1 mW/m.K2 ...

Published
2016
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18. The impact of charge transfer and structural disorder on the thermoelectric properties of cobalt intercalated TiS2

Author

Gabin Guélou, Paz Vaqueiro, Jesús Prado-Gonjal, Anthony V. Powell, Winfried Kockelmann, Tristan Barbier, Emmanuel Guilmeau, Sylvie Hébert, University of Reading (UOR), Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), 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), Science and Technology Facilities Council (STFC), 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), and Normandie Université (NU)-Institut de Chimie du CNRS (INC)

Subjects
Materials science, Neutron diffraction, Thermoelectric equipment, chemistry.chemical_element, 02 engineering and technology, Charge carriers, Thermal transport properties, 010402 general chemistry, 01 natural sciences, Electrically conductive, Thermal conductivity, Charge transfer, Electric conductivity, Van der Waals forces, Concomitant reduction, Thermoelectric performance, Electrical resistivity and conductivity, Vacancy defect, Thermoelectric effect, Materials Chemistry, Electrical conductivity, [CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM]Chemical Sciences, Thermal analysis, General Chemistry, Cobalt, Thermoanalysis, Thermoelectricity, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Crystallography, chemistry, Thermoelectric properties, Transport properties, Charge carrier, Carrier concentration, Powder neutron diffraction, 0210 nano-technology, Lattice contribution
Abstract

International audience; A family of phases, CoxTiS2 (0 ≤ x ≤ 0.75) has been prepared and characterised by powder X-ray and neutron diffraction, electrical and thermal transport property measurements, thermal analysis and SQUID magnetometry. With increasing cobalt content, the structure evolves from a disordered arrangement of cobalt ions in octahedral sites located in the van der Waals' gap (x ≤ 0.2), through three different ordered vacancy phases, to a second disordered phase at x ≥ 0.67. Powder neutron diffraction reveals that both octahedral and tetrahedral inter-layer sites are occupied in Co0.67TiS2. Charge transfer from the cobalt guest to the TiS2 host affords a systematic tuning of the electrical and thermal transport properties. At low levels of cobalt intercalation (x andlt; 0.1), the charge transfer increases the electrical conductivity sufficiently to offset the concomitant reduction in |S|. This, together with a reduction in the overall thermal conductivity leads to thermoelectric figures of merit that are 25% higher than that of TiS2, ZT reaching 0.30 at 573 K for CoxTiS2 with 0.04 ≤ x ≤ 0.08. Whilst the electrical conductivity is further increased at higher cobalt contents, the reduction in |S| is more marked due to the higher charge carrier concentration. Furthermore both the charge carrier and lattice contributions to the thermal conductivity are increased in the electrically conductive ordered-vacancy phases, with the result that the thermoelectric performance is significantly degraded. These results illustrate the competition between the effects of charge transfer from guest to host and the disorder generated when cobalt cations are incorporated in the inter-layer space. © The Royal Society of Chemistry 2016.

Published
2016
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19. Silver intercalation in SPS dense TiS2: staging and thermoelectric properties

Author

Emmanuel Guilmeau, Antoine Maignan, Yohann Bréard, Vladimir V. Roddatis, Tristan Barbier, Oleg I. Lebedev, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), 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), CIC ENERGIGUNE - Parque Tecnol Alava, Laboratoire de Microélectronique et de Physique des Semiconducteurs (LaMIPS), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-NXP Semiconductors [France]-Presto Engineering Europe, 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), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Université de Caen Normandie (UNICAEN), and Normandie Université (NU)-NXP Semiconductors [France]

Subjects
Materials science, Silver, Intercalation (chemistry), Analytical chemistry, Spark plasma sintering, 02 engineering and technology, 01 natural sciences, Inorganic Chemistry, symbols.namesake, Solid-liquid-vapor, Structural disorders, Thermal conductivity, Charge transfer, Temperature range, Sintering, Van der Waals forces, Electrical resistivity and conductivity, Seebeck coefficient, 0103 physical sciences, Thermoelectric effect, Polycrystalline samples, [CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM]Chemical Sciences, 010302 applied physics, Intercalated compounds, Electric power factor, Lattice thermal conductivity, Thermoelectricity, [CHIM.MATE]Chemical Sciences/Material chemistry, Atmospheric temperature range, 021001 nanoscience & nanotechnology, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Thermoelectric properties, Different stages, symbols, van der Waals force, 0210 nano-technology
Abstract

International audience; Polycrystalline samples in the series AgxTiS2 with x varying from 0 to 0.2 were prepared using solid-liquid-vapor reaction and spark plasma sintering. Depending on the x content, it is found that different stages can occur with intercalation, from the so-called 1T-TiS2 (stage 1) to ordered Ag1/6TiS2 (stage 2). Randomly intercalated Ag cations in the van der Waals gap of stage 1 and stage 2 based TiS2 structures induce a strong decrease of lattice thermal conductivity through structural disorder. A decrease in electrical resistivity and the absolute value of the Seebeck coefficient with increasing Ag content supports also the charge transfer to the Ti 3d conduction band, enhancing the power factor in the specific temperature range. Thus, the combined effects of Ag intercalation are beneficial to the improvement in ZT, reaching around 0.45 at 700 K in Ag intercalated compounds. © The Royal Society of Chemistry 2015.

Published
2015
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20. Thermoelectric Properties of (BaCoO3-y)n BaCo8O11.

Author

Ryoji Funahashi and Tristan Barbier

Subjects
*THERMOELECTRIC effects, *HOMOLOGOUS chromosomes, *THERMAL conductivity, *THERMAL properties of condensed matter, *ELECTRICAL resistivity
Abstract

Thermoelectric properties of a homologous oxide system of (BaCoO3-y)nBaCo8O11 have been investigated at 373-973 K in air. All samples show positive Seebeck coefficient values, S, namely p-type character. Electrical resistivity, ρ of BaCoO3-y (n = ∞) decreases monotonically with increasing temperature. On the other hand, a transition in the electrical conduction is observed in the BaCo8O11 (n = 0), Ba2Co9O14 (n = 1), and Ba3Co10O17 (n = 2) around 500 K. Thermal conductivity looks to be decreased by the corner shared CoO6 structure. As the result of these properties, values of dimension-less figure of merit, ZT increase with increasing temperature and reach about 0.03 at 973 K for Ba2Co9O14. Cationic substitution at the Ba site has been carried out. The composition is Ba1.9M0.1Co9O14 (M: Na, Ca, Sr, and La). The substitution by Na is the most effective to enhance the S values at temperatures lower than 573 K. The values of power factor (= S2/ρ) for the samples substituted by Na and Sr are reach 0.1 mW/m.K2 at 773 K. [ABSTRACT FROM AUTHOR]

Published
2016
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21. Thermoelectric Properties of (BaCoO3-y)n BaCo8O11.

Author

Ryoji Funahashi and Tristan Barbier

Subjects
THERMOELECTRIC effects, HOMOLOGOUS chromosomes, THERMAL conductivity, THERMAL properties of condensed matter, ELECTRICAL resistivity
Abstract

Thermoelectric properties of a homologous oxide system of (BaCoO3-y)nBaCo8O11 have been investigated at 373-973 K in air. All samples show positive Seebeck coefficient values, S, namely p-type character. Electrical resistivity, ρ of BaCoO3-y (n = ∞) decreases monotonically with increasing temperature. On the other hand, a transition in the electrical conduction is observed in the BaCo8O11 (n = 0), Ba2Co9O14 (n = 1), and Ba3Co10O17 (n = 2) around 500 K. Thermal conductivity looks to be decreased by the corner shared CoO6 structure. As the result of these properties, values of dimension-less figure of merit, ZT increase with increasing temperature and reach about 0.03 at 973 K for Ba2Co9O14. Cationic substitution at the Ba site has been carried out. The composition is Ba1.9M0.1Co9O14 (M: Na, Ca, Sr, and La). The substitution by Na is the most effective to enhance the S values at temperatures lower than 573 K. The values of power factor (= S2/ρ) for the samples substituted by Na and Sr are reach 0.1 mW/m.K2 at 773 K. [ABSTRACT FROM AUTHOR]

Published
2016
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22. (Invited) Thermoelectric Materials and Modules for High Temperature Application

Author

Tristan Barbier and Ryoji Funahashi

Subjects
Materials science, business.industry, Optoelectronics, Thermoelectric materials, business, Engineering physics
Abstract

Oxide materials are considered to be promising ones because of their durability against high temperature, low cost for producing etc. The misfit CoO2 compounds show high thermoelectric efficiency at high temperature in air. Thermoelectric modules using p-type Ca3Co4O9, one of the CoO2 compounds and n-type CaMnO3 have been produced. The maximum power density against area of the substrate of the module reaches 4.3 kW/m2 at 973 K of the heat source temperature. Cascade modules piled up the oxide and Bi2Te3 modules have been prepared. The maximum power density of 7.8 kW/m2 has been obtained at 1000 K of the heat source temperature. Testing of the cascade systems on industrial furnace and incinerators makes clear the next goals from viewpoints of efficiency and economy for the application of the waste heat recovery by thermoelectrics. In order to improve thermoelectric conversion efficiency, new thermoelectric materials with higher ZT than the above oxides are indispensable. We are developing some new homologous oxides composed of Ba and Co. These layered oxides show low thermal conductivity. A silicide material with a good n-type thermoelectric property has been discovered. This silicide possesses a composition of Mn3-xCrxSi4Al2 (x = 0-0.7) and hexagonal CrSi2 structure. The dimensionless thermoelectric figure of merit ZT reaches 0.21 at 773 K for a non Cr substituted sample at the Mn site and 0.30 at 573 K for a Cr substituted one with x = 0.3. Since oxide passive layer is formed on the surface, electrical resistivity measured at 873 K is constant for two days in air, which indicates good oxidation resistance in air of this material. Thermoelectric modules consisting of 64 pairs of legs have been fabricated using MnSi1.7 and Mn3Si4Al2 devices as p- and n-type legs, respectively. Output power reaches 9.4 W, which corresponds to 2.3 kW/m2 of power density against surface area of the substrate at the heat source temperature of 873 K in air. The Ni–B plating can improve the degradation of the output power for the silicide modules significantly at the heat source temperature of 773 K. Also, the Ni–B plating can decrease the contact resistance at the junctions. Mixing Pt or Pd into the Ag paste effectively improves the durability at the heat-source temperature of 773 K. The output power can be estimated to hold more than 85 % of the initial value after 10 years with current generation of 1A.

Published
2015
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23. (Invited) Recent Advances on the Promising Thermoelectric Oxides Materials

Author

Tristan Barbier and Ryoji Funahashi

Abstract

Because of their ability to convert heat into electricity through the Seebeck effect, there has been increasing interest, in the past few decades, in research into thermoelectric materials for applications in green energy harvesting. Indeed, several sectors, could take advantage of thermoelectric materials capacity to directly convert the waste-heat into electrical energy. These technologies could be available only if performing and cheap thermoelectric materials, operating at temperatures well beyond room temperature, are available. Recently, the improved knowledge of the underlying physics of thermoelectric materials, together with advanced synthesis techniques, has led to the discovery of new material systems with ZT values higher than 2 at elevated temperatures [1-5]. However the generally complex and costly synthesis procedures, together with the expensive, toxic, and rare elements used, present serious impediments to large scale applications. In this context, work therefore continues to focus on the development of thermoelectric materials and processing methods that not only can exhibit high performance, but also possess the potential to be produced on a large scale. In this context oxide materials appear as promising materials due to their wide range of electronic properties ranging from insulating to semiconducting and conducting [6]. Their electronic properties can be engineered by changing their morphology, doping and stoichiometry. Based on this trend, the relationship between the stacking sequence and the thermoelectric properties of the Ba-Co-O system will be discussed. Indeed, the wide range of polytypic structures associated to this system offers a great opportunity for designing an “optimal” structure. [1] J. P. Heremans, V. Jovovic, E. S. Toberer, A. Saramat, K. Kurosaki, A. Charoenphakdee, S. Yamanaka, G. J. Snyder, Science, 321 554–7 (2008). [2] Y. Pei, A. Lalonde, S. Iwanaga, G. J. Snyder, Energy Environ. Sci., 4 [6] 2085-2089 (2011). [3] Y. Pei, X. Shi, A. Lalonde, H. Wang, L. Chen, G. J. Snyder, Nature, 473 [7345] 66–9 (2011). [4].S. N. Girard, J. He, X. Zhou, D. Shoemaker, C. M. Jaworski, C. Uher, V. P. Dravid, J. P. Heremans, M. G. Kanatzidis, J. Am. Chem. Soc., 133 [41] 16588–16597 (2011). [5] K. Biswas, J. He, I. D. Blum, C. Wu, T. P. Hogan, D. N. Seidman, V. P. Dravid, M. G. Kanatzidis, Nature, 490 414–418 (2012). [6] W. E. Pickett, Rev Mod Phys, 61:433–512 (1989).

Published
2015
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