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BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260408T100000
DTEND;TZID=Europe/Paris:20260408T100000
DTSTAMP:20260525T102833
CREATED:20260225T094147Z
LAST-MODIFIED:20260417T102253Z
UID:3622-1775642400-1775642400@www.cnrs-imn.fr
SUMMARY:Tojo RASOANARIVO (PCM) thesis defense
DESCRIPTION:Multiscale modeling of GaN atomic layer etching in chlorinated plasmas\nSummary: Gallium nitride (GaN) is a key material for power electronics devices operating in the radio frequency domain. The miniaturization of architectures makes nanometric control of etching critical. Conventional etching processes using continuous cold plasmas in chlorinated chemistries offer high speeds\, but can induce defects in the material\, impacting device performance and reliability. Atomic layer etching (ALE)\, a cyclic process alternating chemical surface modification and activation by low-energy ion bombardment\, aims to control etching at the atomic scale while improving surface finish. This thesis focuses on the development of a multiscale model of GaN FTA in Cl₂/Ar plasmas. The simulator couples a dynamic global model describing plasma species fluxes and densities with a Monte-Carlo sheath model providing ion energy and angular distribution functions. The results of these first two models are then exploited by a kinetic Monte-Carlo surface model to describe chlorine-induced modification reactions and ion bombardment selectivity at the GaN surface during the ALE process. This surface model is fed by an ab initio study describing Cl-GaN(0001) interactions. Ultimately\, the simulator package makes it possible to link mesoscopic parameters to plasma/surface interactions at the atomic scale\, to gain a deeper understanding of the mechanisms involved and optimize process performance\, such as post-etch GaN surface finish and control of etched thickness per cycle. Ultimately\, this work can be integrated into a digital twin of GaN ALE processes\, to guide the optimization and industrialization of atomic-scale etching.          \nKeywords: semiconductor\, cold plasma process\, etching\, modeling\, multiscale \n\nMultiscale modelling of Atomic Layer Etching of GaN in chlorinated plasmas\nAbstract: Gallium nitride (GaN) is a key material for power electronics devices operating in radiofrequency ranges. The downscaling of architectures makes nanometric control of etching critical. Conventional etching processes using continuous plasmas in chlorinated chemistries offer high etch rates but can induce defects in the material\, degrading device performance and reliability. Atomic layer etching (ALE)\, a cyclic process alternating between chemical surface modification and activation by low-energy ion bombardment\, aims to control etching at the atomic scale while improving the surface state. This thesis focuses on the development of a multiscale model for ALE of GaN in Cl₂/Ar plasmas. The simulator combines a global dynamic model describing plasma species fluxes and densities with a Monte Carlo sheath model providing ions energy and angular distribution functions. The results from these first two models are then used as inputs for a kinetic Monte Carlo surface model to describe chlorine-induced modification reactions and ion bombardment selectivity on the GaN surface during ALE processing. This surface model relies on ab initio study describing Cl-GaN(0001) interactions. The simulator associates mesoscopic parameters to plasma/surface interactions at the atomic scale in order to deepen understanding of the involved mechanisms and optimize process performances\, such as the GaN surface state after etching and etched thickness per cycle. Ultimately\, this work can be integrated into a digital twin for GaN ALE processes to guide the optimization and industrialization of atomic-scale etching.          \nKeywords: semiconductor\, low temperature plasma process\, etching\, modelling\, multiscale
URL:https://www.cnrs-imn.fr/en/event/tojo-rasoanarivo-pcm-thesis-defense/
LOCATION:Amphi IMN
ATTACH;FMTTYPE=image/jpeg:https://www.cnrs-imn.fr/wp-content/uploads/2026/02/rasoanarivo_tojo.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260409T090000
DTEND;TZID=Europe/Paris:20260410T170000
DTSTAMP:20260525T102833
CREATED:20260304T083908Z
LAST-MODIFIED:20260417T122832Z
UID:3433-1775725200-1775840400@www.cnrs-imn.fr
SUMMARY:Journées des Doctorants - JDD 2026
DESCRIPTION:SYRA is delighted to invite you to the Journées Des Doctorants 2026 (JDD2026). Once again\, we are pleased to present the work of our secondyear PhD students\, and to welcome the IMN newcomers. Last year\, a photo contest took place outside the main IMN building (Lombarderie site) during the JDD2025. Students and employees of Nantes University were invited to discover this exhibition\, which aims to open a window on the expertise in materials science developed at the IMN. This year\, to open up this window even further\, a treasure hunt has been organized: scientific riddles linked to IMN’s thematic research are spread across the Lombarderie site. Six panels\, one correct answer at each step and multiple prizes at the end! The JDD2026 is also an opportunity to improve speaking skills\, essential for future conferences\, in a more informal setting. We sincerely hope this event will foster connection between different generations of doctoral students and their research teams\, and encourage them to share their experiences.
URL:https://www.cnrs-imn.fr/en/event/journees-des-doctorants-jdd-2026/
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BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260409T133000
DTEND;TZID=Europe/Paris:20260409T144500
DTSTAMP:20260525T102833
CREATED:20260326T152248Z
LAST-MODIFIED:20260417T102458Z
UID:3393-1775741400-1775745900@www.cnrs-imn.fr
SUMMARY:Christophe VALLEE seminar
DESCRIPTION:More than 50 years of plasma etching innovation: from RIE to ALE… and what’s next? \n \nChristophe VALLEE \nUniversity at Albany\, CNSE\, USA \nIn 1974\, in their paper entitled “RF sputter-etching by fluoro-hloro-hydrocarbon gases”\, N. Hosokawa et al. proposed to combine energetic ions with volatile products for plasma etching [1]. They came up with the idea of replacing argon with fluoro-chloro-hydrocarbon gases in rf diode sputtering equipment. They observed very high sputter-etching speeds\, 10 to 20 times higher than those normally encountered with Si or Al. This marked the beginning of plasma etching combining ions and radicals\, Reactive Ion Etching (RIE).    \nWith this presentation I will discuss the following 50 years of work that followed the pioneer work of Hosokawa et al\, in understanding\, designing and optimizing plasma etching processes and reactors. I will show how plasma etching was modified to enable the transistor scaling areas: geometrical scaling (1975-2002)\, equivalent scaling (2003-2024)\, and 3D power scaling with transition to complete vertical structures (2025-…). The first scaling area saw the emergence of new reactors enabling the decoupling of flow and energy. The second was accomplished thanks to the transition from continuous flow processes to pulsed processes (pulsed plasma etching\, Atomic Layer Etching). As we enter the third scaling area\, selectivity will become predominant and temperature control will be a key parameter for the plasma etching processes\, as illustrated by the recent development of cryogenic etching. Finally\, future challenges for etching processes to meet sustainability and environmental concerns will also be addressed.      \nHaving completed my thesis at IMN\, I will take a little time at the beginning of my presentation to explain my career path since my thesis and what my current research activity is at CNSE.
URL:https://www.cnrs-imn.fr/en/event/christophe-vallee-seminar/
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BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260409T133000
DTEND;TZID=Europe/Paris:20260409T150000
DTSTAMP:20260525T102833
CREATED:20260225T085537Z
LAST-MODIFIED:20260417T102700Z
UID:3629-1775741400-1775746800@www.cnrs-imn.fr
SUMMARY:Jeudis de la Chimie du Solide seminar - Julien Varignon (CRISMAT Caen)
DESCRIPTION:Charge and orbital orders drive superconductivity in complex oxides \n \nJulien Varignon \nCRISMAT Laboratory\, CNRS UMR 6508\, ENSICAEN\, Normandie University \nSuperconductivity\, characterized by zero electrical resistance and expulsion of the magnetic field\, remains limited by relatively modest critical temperatures Tc\, reaching 135 K at best in cuprates at ambient pressure. In complex oxides\, understanding the mechanisms by which Tc can be increased is a major challenge\, particularly from the point of view of electronic and structural chemistry.  \nOxides derived from Ruddlesden-Popper An+1BnO3n+1-type phases play a central role in this issue. In these systems\, superconductivity frequently appears close to a transition between an insulating and a metallic phase. This transition is often associated with the disappearance of electronic orders such as charge orders (cationic dismutation) or orbitals\, frequently linked to Jahn-Teller-type structural instabilities.   \nIn this seminar\, I show\, using first-principles simulations based on density functional theory (DFT)\, that superconductivity emerges systematically in the vicinity of these ordered phases. Even if these orders disappear in the metallic phase\, their fluctuations persist and generate sufficient electron-phonon coupling to initiate superconductivity.  \nThese results suggest that ordered insulating and superconducting phases share a common origin1\,2. Finally\, I demonstrate that structural distortions of O6 octahedral lattices\, such as rotations\, can modulate this electron-phonon coupling. This opens the way to an oxide structural engineering strategy to optimize Tc.   \n______________________ \n1. J. Varignon\, M. Bibes\, and A. Zunger\, Nat. Comm. 10\, 1658 (2019)\n2. A. A. Carrasco-Alvarez\, S. Petit\, W. Prellier\, M. Bibes\, and J. Varignon\, Nat.   Comm. 16\, 1458 (2025) \n  \nhttps://univ-nantes-fr.zoom.us/j/88146334543?pwd=8GL4UQasDKOmY9g5XmabSbPm0nDZx7.1\nMeeting ID: 881 4633 4543\nSecret code: 468276
URL:https://www.cnrs-imn.fr/en/event/jeudis-de-la-chimie-du-solide-seminar-julien-varignon-crismat-caen/
LOCATION:Videoconferencing
ATTACH;FMTTYPE=image/jpeg:https://www.cnrs-imn.fr/wp-content/uploads/2026/02/Julien_Varignon-e1775722631458.jpg
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BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260507T100000
DTEND;TZID=Europe/Paris:20260507T113000
DTSTAMP:20260525T102833
CREATED:20260414T144001Z
LAST-MODIFIED:20260504T195824Z
UID:5837-1778148000-1778153400@www.cnrs-imn.fr
SUMMARY:Chen-Wei Liu Seminar
DESCRIPTION:Chen-Wei Liu (劉鎮維) \nNDHU chair professor\, Department of Chemistry\, National Dong Hwa University\, \nHualien\, Taiwan 97401 \nchenwei@gms.ndhu.edu.tw \n  \nHydride-doped Coinage Metal Nanoclusters: From Superatomic Alloys to Superclusters \nHydride\, H- (1s2)\, the smallest closed shell anion\, is a one-negative charge ligand widely used to stabilize metallic compounds. Aside from its characteristic NMR signals\, detailed characterizations of hydride location within metal clusters are problematic due to its near-invisible X-ray scattering length. Therefore\, chemists working on polyhydrido metal clusters must be very cautious. In 2009\, the Liu group first succeeded in the isolation of a hydride insertion product\, Cu8(H)L6 (L = E2PR2\, E = S\, Se)\, where significant metal kernel distortions compared to an empty CuI 8 cube (stabilized by six dichalcophosphate ligands) suggested the additional hydride was located at the center of Cu8 cage. This work kicks off the chemistry of coinage metal hydrides created by the Liu group. During a span of 17 years\, we have uncovered four important concepts: (1) hydride additions can assist the growth of nanoscale copper clusters\, (2) interstitial hydrides in nanoclusters can reduce M(I) (M = Cu\, Ag\, Au) to M(0) and form stable superatoms\, (3) the interstitial hydride coordinated to Ni\, Pd\, Pt\, Rh\, Ir\, Ru within Ag- and Cu-rich clusters can behave as “metallic” hydrogen (i.e. to provide its 1s(H) electron to the cluster electron count)\, (4) the first synthesis of a three-dimensional self-assembled supercluster formed by the tetrahedral arrangement of four IrH2@Ag12 icosahedra\, reminiscent of a tetrahedrane. This presentation will focus on the synthesis\, structures\, and bonding of hydride-doped precious metal nanoclusters\, which are indeed structurally precise\, ultra-small nanoparticles\, as well as its remarkable HER activities catalyzed by a 2-electron palladium(platinum)/copper superatomic alloy\, [Pd/Pt/HCu11{S2P(O iPr)2}6(C≡CPh)4]. \n  \nReferences \n[1] Dhayal\, R. S.; van Zyl\, W. E.; Liu\, C. W. Acc. Chem. Res. 2016\, 49\, 86 – 95. \n[2] Sharma\, S.; Chakrahari\, K. K.; Saillard\, J.-Y.; Liu\, C. W. Acc. Chem. Res. 2018\, 51\, 2475 – 2483. \n[3] Artem’ev\, A. V.; Liu\, C. W. Chem. Commun. 2023\, 59\, 7182 – 7195. \n[4] Chiu\, T.-H.; Liao\, J.-H.; Silalahi\, R. P. B.; Pillay\, M. N.; Liu\, C. W. Nanoscale Horiz. 2024\, 9\, 675 – 692. \n  \n  \nContact: Camille Latouche (MIOPS)
URL:https://www.cnrs-imn.fr/en/event/chen-wei-liu-seminar/
LOCATION:Amphi IMN
ATTACH;FMTTYPE=image/jpeg:https://www.cnrs-imn.fr/wp-content/uploads/2026/04/Chen-Wei_Liu.jpg
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BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260507T133000
DTEND;TZID=Europe/Paris:20260507T150000
DTSTAMP:20260525T102833
CREATED:20260417T100835Z
LAST-MODIFIED:20260520T161708Z
UID:5939-1778160600-1778166000@www.cnrs-imn.fr
SUMMARY:Jeudis de la Chimie du Solide seminar - João Rocha (CICECO-Aveiro)
DESCRIPTION:Functional Porous Materials: From Transition-Metal and Lanthanide Silicates to MOFs \n \nJoão Rocha \nDepartment of Chemistry\, CICECO-Aveiro Institute of Materials\, University of Aveiro\, Portugal \nBeyond zeolites\, certain microporous silicates constructed from transition metal- and lanthanide-containing heteropolyhedra constitute a particularly promising class of functional materials. In addition to the properties conventionally associated with zeolites\, these materials may also exhibit magnetic and luminescent behaviour of considerable interest. In my laboratory\, we have demonstrated the potential application of these materials in hydrogen/nitrogen separation membranes\, light-emitting devices [1]\, and the treatment of hyperkalaemia (elevated serum K+ levels)\, culminating in the development of a drug that is now available on the market.   \nIn parallel\, our research on metal-organic frameworks (MOFs) seeks to exploit the remarkable modularity of these nanoporous hybrid materials\, which are composed of polyatomic metal assemblies interconnected by organic ligands. Although MOFs are generally less robust than zeolitic materials\, they offer a decisive advantage in terms of rational design and post-synthetic functionalization. Within this context\, we have developed several research directions focused on luminescence-based thermometry\, anti-mosquito textiles\, and the capture of uranyl ions in aqueous media. We have furthermore designed MOFs based on tetrathiafulvalene phosphonates and lanthanide ions\, exhibiting mixed ionic and electronic conductivity [2]\, thereby opening significant prospects for applications in (opto)electronics\, catalysis\, and energy storage.    \n______________________ \n[1] Wang\, Z.; Ananias\, D.; Carné-Sánchez\, A.; Brites\, C.D.S.; Imaz\, I.; Maspoch\, D.; Rocha\, J.; Carlos\, L.D. Adv. Funct. Mater. 2015\, 25\, 2824-2830.\n[2] Ribeiro\, C.; Tan\, B.; Figueira\, F.; Mendes\, R.; Calbo\, J.; Valente\, G.; Escamilla\, P.; Paz\, F.A.; Rocha\, J.; Dincă\, M.; Souto\, M. J. Am. Chem. Soc. 2025\, 147\, 63-68. \n  \nhttps://univ-nantes-fr.zoom.us/s/89388274201
URL:https://www.cnrs-imn.fr/en/event/jeudis-de-la-chimie-du-solide-seminar-joao-rocha-ciceco-aveiro/
LOCATION:Videoconferencing
ATTACH;FMTTYPE=image/jpeg:https://www.cnrs-imn.fr/wp-content/uploads/2026/04/Joao_Rocha.jpg
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BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260528T110000
DTEND;TZID=Europe/Paris:20260528T123000
DTSTAMP:20260525T102833
CREATED:20260512T161545Z
LAST-MODIFIED:20260512T162131Z
UID:6155-1779966000-1779971400@www.cnrs-imn.fr
SUMMARY:Babak Anasori seminar
DESCRIPTION:Composition-Structure-Property Relationships in MXenes \n \nBabak ANASORI\nReilly Rising Star Associate Professor\nSchool of Materials Engineering and School of Mechanical Engineering\nPurdue University\, West Lafayette\, IN 47907\, USA\n \nMXenes are a large family of 2D transition metal carbides\, carbonitrides\, and nitrides with over 100 synthesized compositions to date. The rapid growth of the MXene family is driven by designer chemistry control of their composition and structure\, including the transition metal and surface functional groups\, the non-metal sublattice\, and atomic-layer configurations. This compositional diversity controls chemical ordering\, defect formation\, and surface chemistry\, ultimately determining MXenes properties. In addition to their chemical and structural diversity\, as-synthesized MXenes exhibit high electrical conductivity\, hydrophilicity\, functionalized surfaces\, and tunable electronic\, chemical\, and mechanical properties.    \nIn this talk\, I will start with a brief overview of the possible compositions and structures of MXenes\, then focus on our recent efforts on medium- and high-entropy MXenes and defect engineering to control stability\, phase transformation\, and functional properties. I will discuss our work on the transition from order to disorder at sub-nanometer thicknesses across 40 different MXenes with two to nine transition metals due to entropy effects. I will also present how controlling defects\, including metal and non-metal vacancies and carbon substitution with nitrogen\, enables tuning of oxidation resistance\, electrocatalytic behavior\, and high-temperature stability.   \n  \nBio:Dr. Babak Anasori is the Reilly Rising Star Associate Professor at Purdue University\, with joint appointments in the Schools of Materials Engineering and Mechanical Engineering. He also serves as the Editor-in-Chief of Graphene and 2D Materials\, a Springer-Nature journal. Dr. Anasori received his PhD from Drexel University in 2014 in the Department of Materials Science and Engineering\, the birthplace of MXenes. Dr. Anasori has authored over 210 refereed publications on MXenes and their precursors and has been recognized as a Web of Science Highly Cited Researcher since 2019. He has received several international awards\, including the 2016 Materials Research Society (MRS) Postdoctoral Award\, the 2021 Drexel University 40-under-40\, the 2021 Waterloo Institute for Nanotechnology (WIN) Rising Star Award in Nanoscience and Nanotechnology\, the 2024 Early Discovery Award by the American Ceramic Society (ACerS)\, the 2024 Kavli Foundation Early Career Lectureship in Materials Science by MRS\, and the 2026 Purdue University Faculty Excellence Award for Early Career Research. Dr. Anasori’s research lab focuses on developing novel 2D carbide and carbonitride MXenes for various applications\, including energy generation\, electromagnetic interference shielding\, and ultra-high temperature and extreme environments.          \n  \nContact: Philippe Moreau (ST2E)
URL:https://www.cnrs-imn.fr/en/event/mathieu-g-seminar-silly-2/
LOCATION:Amphi IMN
ATTACH;FMTTYPE=image/jpeg:https://www.cnrs-imn.fr/wp-content/uploads/2026/05/Anasori_Babak.jpg
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BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260604T143000
DTEND;TZID=Europe/Paris:20260604T160000
DTSTAMP:20260525T102833
CREATED:20260416T143002Z
LAST-MODIFIED:20260417T101151Z
UID:5912-1780583400-1780588800@www.cnrs-imn.fr
SUMMARY:Mathieu G. Seminar Silly
DESCRIPTION:Soft X-ray High-Resolution and Time-Resolved Photoemission: Surface Chemistry and Charge Dynamics in Photoactive Materials \n \nMathieu G. SILLY\nTEMPO Beamline\, Synchrotron SOLEIL\, France \nPhotoactive materials – from transition-metal oxides to semiconductors and hybrid heterostructures – exhibit complex surface and interface phenomena that critically govern their optical\, catalytic\, and electronic performance. Understanding the interplay between surface chemistry\, defects\, and charge dynamics\, over timescales ranging from a few tens of picoseconds up to one second\, is essential for elucidating their photoactivity.  \nHigh-resolution photoemission spectroscopy (HRPES) provides chemical selectivity and surface sensitivity\, enabling the identification of oxidation states\, defects\, and interfacial electronic structures. When combined with time-resolved photoemission spectroscopy (TRPES)\, this approach allows direct observation of fast picosecond-scale dynamics – such as charge transfer and optically induced electronic relaxation – as well as slower nanosecond-to-second processes\, including trap-mediated recombination\, surface photovoltage relaxations\, or charge drift on mesoscopic scales.  \nThese multi-timescale capabilities are particularly relevant for systems such as hematite under environmental conditions\, passivated silicon surfaces\, or colloidal nanoparticles coupled to oxides\, where simultaneous insight into local chemistry and transient charge dynamics is crucial. \nThe TEMPO beamline at the SOLEIL synchrotron\, dedicated to high-resolution core-level photoemission and pump-probe experiments over the ps-s temporal range\, provides a unique platform for probing light-matter interactions with both chemical and temporal sensitivity. The combination of HRPES and TRPES thus offers a powerful framework to unravel the mechanisms governing photoactivity and to guide the design of more efficient and durable photoactive materials.  \n  \nContact: Mireille Richard-Plouet (PCM)
URL:https://www.cnrs-imn.fr/en/event/mathieu-g-seminar-silly/
LOCATION:Amphi IMN
ATTACH;FMTTYPE=image/png:https://www.cnrs-imn.fr/wp-content/uploads/2026/04/Silly_Mathieu.png
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BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260609T140000
DTEND;TZID=Europe/Paris:20260611T140000
DTSTAMP:20260525T102833
CREATED:20260413T124103Z
LAST-MODIFIED:20260413T124103Z
UID:5763-1781013600-1781186400@www.cnrs-imn.fr
SUMMARY:JEELS Congress
DESCRIPTION:
URL:https://www.cnrs-imn.fr/en/event/jeels-congress/
LOCATION:Amphi IMN
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260611T133000
DTEND;TZID=Europe/Paris:20260611T150000
DTSTAMP:20260525T102833
CREATED:20260520T161228Z
LAST-MODIFIED:20260520T162038Z
UID:6182-1781184600-1781190000@www.cnrs-imn.fr
SUMMARY:Jeudis de la Chimie du Solide seminar - Céline Barreteau (ICMPE Thiais)
DESCRIPTION:Screening new thermoelectric intermetallic compounds using high-throughput computation and machine learning \n \nCéline Barreteau \nICMPE\, CNRS-UMR 7182\, 2-4 rue Henri Dunant\, 94320\, Thiais\, France \nIn the current economic and ecological context\, the development of alternative energy production is a major challenge. With this in mind\, thermoelectric materials\, which convert heat flow into a temperature gradient (and vice versa)\, offer numerous advantages: no moving parts\, high reliability\, …. However\, they are still confined to niche applications due to their high production costs and low yields. New high-performance materials are therefore needed to increase the use of this technology.    \nTo facilitate and accelerate the search for new candidates\, a dual approach\, combining first-principles calculations and experiments\, is of interest. For a wide range of compositions\, our method combines high-throughput calculations to identify stable\, non-metallic compounds\, with experimental studies of the most promising screened materials.  \nInitially\, we focused on ternary T-M-X intermetallic compounds\, with T a transition metal\, rare earth or alkaline earth metal\, M an element from the first line of transition metals and X\, a sp element [1\,2]. Thus\, for dozens of prototypes\, all possible T-M-X combinations were investigated by DFT calculations. Following this theoretical screening\, experimental investigations were carried out to confirm the theoretical results\, particularly with regard to stability and thermoelectric properties [3].   \nNow\, in our quest for more promising new materials\, we are continuing to improve our screening method to increase the complexity and type of compounds\, while reducing the number and duration of calculations. To this end\, Machine Learning techniques have been applied to certain intermetallic prototypes\, such as Heuslers\, to optimize our screening [4].  \n  \n______________________ \n[1] Barreteau\, C. et al.\, Optimization of criteria for an efficient screening of new thermoelectric compounds: the TiNiSi structure-type as a case-study\, ACS Combinatorial Sciences\, 22\, 813-820\, (2020)\, https://doi.org/10.1021/acscombsci.0c00133 \n[2] Barreteau\, C. et al\, Looking for new thermoelectric materials among TMX intermetallics using high-throughput calculations\, Computational Material Science\, 156\, 96-103 (2019)\, http://doi.org/10.1016/j.commatsci.2018.09.030 \n[3] Moll\, A. et al\, SrCuP and SrCuSb Zintl phases as potential thermoelectric materials\, J. All. Comp. 924\, 169123 (2023) https://doi.org/10.1016/j.jallcom.2023.169123 \n[4] Xie\, R. et al\, Screening new quaternary semiconductor Heusler compounds by machine-learning methods\, Chem. Mater. 35\, 7615-7627 (2023) https://doi.org/10.1021/acs.chemmater.3c01323   \n  \n 
URL:https://www.cnrs-imn.fr/en/event/jeudis-de-la-chimie-du-solide-seminar-celine-barreteau-icmpe-thiais/
LOCATION:Videoconferencing
ATTACH;FMTTYPE=image/jpeg:https://www.cnrs-imn.fr/wp-content/uploads/2026/04/Joao_Rocha.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20260722T140000
DTEND;TZID=Europe/Paris:20260722T153000
DTSTAMP:20260525T102833
CREATED:20260520T163136Z
LAST-MODIFIED:20260520T163317Z
UID:6199-1784728800-1784734200@www.cnrs-imn.fr
SUMMARY:Romain Berthelot Seminar
DESCRIPTION:Solid-state design of crystalline alkali-mixed layered compounds \n \nRomain BERTHELOT \nCharles Gerhardt Institute of Montpellier\, CNRS\, UM\, ENSCM\, France \nSolid-state chemists have long explored alkali transition metal layered compounds as a playground for discovering new compositions and tuning crystal structures and physical or electrochemical properties. In these materials\, cation substitution within the transition metal layers is generally facilitated by the similar ionic radii of many elements in octahedral coordination. By contrast\, modifying the interlayer space is far more constrained\, as differences in size and site symmetry hinder the incorporation of multiple alkali elements.   \nHere\, we show that these limitations can be overcome through carefully designed synthesis strategies. A range of layered oxides and sulfides is explored\, yielding new mixed-alkali compositions with two distinct cation distributions: either a disordered arrangement within a single interlayer or an ordered stacking of chemically distinct alkali layers.  \nResolving these complex structures remains a central challenge\, particularly with regard to locating alkali ions and accounting for stacking defects. To address this\, we combine complementary techniques: X-ray and neutron powder diffraction to probe long-range order\, alongside high-resolution transmission electron microscopy and solid-state NMR to access local structural environments. Density functional theory calculations further rationalize the stability of the observed arrangements.   \nTogether\, these results uncover new structural motifs in layered materials and provide guidelines for the targeted design of mixed-alkali transition metal layered compounds. \n \nContact: Romain Wernert/Thierry Brousse (ST2E)
URL:https://www.cnrs-imn.fr/en/event/mathieu-g-seminar-silly-3/
LOCATION:Amphi IMN
ATTACH;FMTTYPE=image/jpeg:https://www.cnrs-imn.fr/wp-content/uploads/2026/05/Romain_Berthelot.jpg
END:VEVENT
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