Abstract : Developing new materials is essential to address the challenges of tomorrow, whether it is producing and storing energy, designing new catalytic solutions, protecting the environment, or improving health. Understanding the materials of the future can no longer rely on a single analytical method: it requires combining complementary techniques and exploring matter across multiple scales. Electron microscopy plays a key role in this endeavor, allowing us today to observe nanomaterials in action with unparalleled resolution, under conditions close to their formation or real-world use. The conference will also highlight the complementarity between electron microscopy and other advanced techniques, such as those based on synchrotron radiation..
This conference will be presented jointly by:
Prof. Clément SANCHEZ, Collège de France – USIAS (conférence en français)
Clément Sanchez est professeur émérite au Collège de France, titulaire de la chaire Chimie des matériaux hybrides et d’une chaire à l’USIAS de Strasbourg. Ancien directeur du Laboratoire de Chimie de la Matière Condensée de Paris, il a mené une grande partie de sa carrière au CNRS, où il a développé la « chimie douce » pour la synthèse de nanomatériaux hybrides. Ses recherches portent sur la nanochimie et les propriétés des gels et matériaux hybrides organiques-inorganiques, avec une forte inspiration tirée du vivant et un souci d’adaptation aux enjeux environnementaux. Lauréat de plusieurs prix, il est également membre de différentes académies des sciences.
Prof. Gianluigi BOTTON, Synchrotron « Diamond Light Source » (UK) (Conférence en anglais)
Depuis octobre 2023, le Professeur Botton est Directeur Général du Diamond Light Source, le synchrotron national du Royaume-Uni. Il est également chercheur à l’Université McMaster, où il a occupé de 2002 à 2023 une Chaire de recherche du gouvernement canadien en microscopie électronique appliquée aux matériaux. Ancien Directeur scientifique du Canadian Light Source, il est aussi le fondateur du Canadian Centre for Electron Microscopy (CCEM), une infrastructure nationale de microscopie ultrahaute résolution. Lauréat de nombreuses distinctions internationales, il est Fellow de la Microscopy Society of America et de la Royal Society of Canada, et contribue activement à plusieurs revues scientifiques comme rédacteur invité ou membre de comités éditoriaux.
Program under construction
Speakers:
Prof. Nigel Browning, Director of the Albert Crewe Centre, University of Liverpool, UK (TEM & AI)
Prof. Marc-Georg Villinger, Technical University of Munich (In situ TEM, energy materials)
Prof. Joke Hadermann, EMAT Antwerp (crystallography, electron diffraction)
Prof. Naoya Shibata, The University of Tokyo (TEM on JEOL microscopes)
Prof. Odile Stephan, LPS Orsay (EELS-TEM)
Dr. Arnaud Demortiere, LRCS Amiens (Electrochemistry in TEM)
Dr. Sophie Meuret, CEMES Toulouse (Ultrafast TEM)
Dr. Damien Alloyeau, MPQ Paris (Liquid TEM)
Dr. Patrick Schultz, IGBMC Strasbourg (TEM in biology)
Gracie Chaney (Sorbonne Université, Laboratoire de Chimie Theorique PARIS)
Abstract : Although ab initio molecular dynamics (AIMD) can predict the chemical reactions in materials with quantum accuracy, it suffers from computational inefficiency that constrains simulations in size (<1000 atoms) and time (<100 ps). Machine learned interatomic potentials (MLIPs) bridge the gap between quantum accuracy and classical efficiency by learning the potential energy surface of the system from the AIMD data and using it as the force field in classical molecular dynamics (CMD) simulations. In this presentation, I will feature two very different systems for which I have used MLIPS. The first is the interface of a solid-state battery consisting of a Li-metal anode and an argyrodyte Li6PS5Cl solid-state electrolyte. By using a moment-tensor potential scheme we were able to generate an MLIP that accurately predicted the short- and long-term growth of the solid-electrolyte interphase region initiated by reduction of the electrolyte by the anodic Li [2]. The second system consists of a dense liquid of NH3/H2O/CH4 subjected to extreme temperatures (3000 K) and pressures (22-69GPa). In this case, we used an equivariant neural network potential [3] trained on an even distribution of NH3/H2O/CH4 structures of various NH3 amounts (4, 8, and 12). Both the AIMD and MLIP+MD simulations showed that increasing pressure at high temperature induces water ionization and begins a process involving the formation of transient CH5+ molecules and highly reactive carbocations that drive hydrocarbon chain growth toward nanodiamonds. Such results could be useful for understanding the dynamics within icy giant planets, such as Uranus and Neptune.
[1] Ivan S Novikov et al. 2021 Mach. Learn.: Sci. Technol. 2, 025002
[2] Gracie Chaney et al. 2024 ACS Appl. Mater. Interfaces 16, 19, 24624–24630
[3] Musaelian, A., Batzner, S., Johansson, A. et al. (2023) Nat Commun 14, 579
Contactc : Hervé Bulou (0388107095 – herve.bulou@ipcms.unistra.fr) et Christine Goyhenex (0388107097 – christine.goyhenex@ipcms.unistra.fr)
Aliou Sadia TRAORÉ (IPCMS – DSI)
This work was carried out under the supervision of Prof. Ovidiu ERSEN (DSI) and Dr. Valérie BRIOIS (Synchrotron SOLEIL).
Aram Yoon (Shell Energy Transition Center, Amsterdam)
Abstract : Electrocatalysis plays a pivotal role in various energy conversion and storage applications, including fuel cells, electrolyzers, and batteries. It facilitates the conversion of chemicals from one form to another, making it essential for clean and sustainable energy technologies. Transition metal oxides show great promise in this regard, as they are abundant on Earth and can modify their electrical and chemical properties by adjusting their oxidation state through surface and interface engineering. To effectively harness these materials in energy conversion devices, it is imperative to gain insights into how catalysts’ structures behave in working environments, as this significantly influences chemical conversions and the catalysts’ own chemical status. However, investigating the structure and chemistry of electrocatalysts under electrochemical reaction conditions is a challenging endeavor. Electrochemical systems involve reactions and transformations occurring at multiphase boundaries, including solid-solid and solid-liquid interfaces. This complexity necessitates the use of diverse techniques to probe these interfaces, further complicated by the need to maintain the electrolyte and applied potential.
In my presentation, I will delve into the behavior of Cu2O catalysts under dynamic reaction conditions, employing a multimodal approach centered on in situ Electrochemical Cell Transmission Electron Microscopy (EC-TEM). This approach will focus on two conversion reactions involving Cu2O catalysts: electrochemical CO2 reduction and nitrate reduction. Through this investigation, I will demonstrate structural changes of Cu2O catalysts during redox reactions. The primary emphasis will be on correlating various operando techniques, such as X-ray absorption microscopy and spectroscopy, with electrochemical characterization to gain a comprehensive understanding of how structural heterogeneity impacts catalysis.
Contact : Maria Letizia De Marco (0388107028 – maria-letizia.demarco@ipcms.unistra.fr)
Alex FETIDA (IPCMS / DSI)
This work was conducted under the supervision of Dr. Laurent Limot (DSI).
Speaker: Prof. Kenneth Beyerlein (Institut national de la recherche scientifique, Varennes, Québec, Canada)
Abstract here
This research work was conducted under the guidance of Dr. Christine Boeglin (DSI, IPCMS).
The defense is scheduled on Friday, 5th April 2024, at 10:30 AM in the IPCMS auditorium.
Maria Chatzieleftheriou (CPHT, Ecole Polytechnique, Palaiseau)
Abstract : voir affiche jointe
Sophie WEBER (ETH-Zurich, Department of Materials, Zurich, Switzerland)
Theoretical arguments [1,2] and experimental measurements [3-6] have definitively shown that antiferromagnets (AFMs) with particular bulk symmetries can possess a nonzero magnetic dipole moment per unit area or “surface magnetization” on certain surface facets. Such surface magnetization underlies intriguing physical phenomena like interfacial magnetic coupling, and can be used as a readout method of antiferromagnetic domains. However, a universal description and understanding of antiferromagnetic surface magnetization is lacking. I first introduce a classification system based on whether the surface magnetization is sensitive or robust to roughness, and on whether the magnetic dipoles at the surface of interest are compensated or uncompensated. I then show that every type of surface magnetization can be identified and understood in terms of bulk magnetic multipoles, which are already established as symmetry indicators for bulk magnetoelectric responses [7]. This intimate correspondence between antiferromagnetic surface magnetization and magnetoelectric responses at both linear and higher orders reveals that selection and control of the antiferromagnetic order parameter via magnetoelectric annealing may be possible in many more materials and surfaces than previously believed. I use density functional calculations to illustrate that nominally compensated (10-10) and (-12-10) surfaces in magnetoelectric Cr2O3 develop a finite magnetization density at the surface, in agreement with our predictions based on both group theory and the ordering of the bulk multipoles. Finally, I present magnetotransport results by collaborators confirming our ab-initio and theoretical predictions of finite magnetization on these surfaces. Our analysis [8,9] provides a comprehensive basis for understanding the surface magnetic properties and their intimate correspondence to bulk magnetoelectric effects in antiferromagnets, and may have important implications for technologically relevant phenomena such as exchange bias coupling.
[1] A. F. Andreev, JETP Lett. 63, 756 (1996)
[2] K. D. Belashchenko, Phys. Rev. Lett. 105, 147204 (2010)
[3] X. H et al, Nature Mat. 9, 579 (2010)
[4] N. Wu et al., Phys. Rev. Lett. 106, 087202 (2011)
[5] P. Appel et al., Nano Lett. 19, 1682 (2019)
[6] M. S. Wörnle et al., Phys. Rev. B 103, 094426 (2021)
[7] N. A. Spaldin et al., Phys. Rev. B 88, 094429 (2013)
[8] S. F. Weber et al., arXiv:2306.06631 (2023)
[9] O. V. Pylypovskyi, S. F. Weber et al., arXiv 2310.13438 (2023)
Contact : Mébarek ALOUANI : mebarek.alouani@ipcms.unistra.fr
