Invited Speakers
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Brahim DKHIL, Université Paris-Saclay, CentraleSupélec, Laboratoire SPMS, CNRS-UMR8580, 91190 Gif-sur-Yvette, France
Ferroelectric materials: an essential platform for current and future environmental and energy challenges
Among electroactive materials, ferroelectrics are fascinating ones that offer rich physics at the intersection of several branches of condensed matter, materials science, and chemistry. As such, they are the subject of intense interest, often leading to the discovery of new and intriguing phenomena, continually enriching the field and paving the way for new functionalities with promising applications. Highly responsive to several external stimuli, they are essentially multifunctional materials, making them very interesting for applications in sensors, actuators, energy storage, energy harvesting or memories. In this presentation, after a brief overview of the diversity of the ferroelectric world, I will show that ferroelectric and related materials can be considered for other applications by focusing on our current work in their use in wastewater treatment and green fuel production to illustrate this diversity and highlight the fantastic potential that such materials can offer in these areas. I will show that ferroelectrics can be useful for multicatalysis, where not only light (photocatalysis) can be used as a stimulus, but also mechanical (piezocatalysis) or thermal (pyrocatalysis) excitations can be used simultaneously to address environmental and energy challenges. More specifically, I will show how we can design ferroelectric and related materials to make them highly efficient catalysts, surpassing the performance of existing materials.
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Stéfan DILHAIRE, Université de Bordeaux, Laboratoire LOMA,CNRS-UMR 5798, France
Thermoelectricity at the Nanoscale: Contact and Contactless Characterization
Understanding thermoelectric phenomena at the nanoscale is essential for the development of advanced energy conversion systems and for thermal management in nanoelectronic devices. At these length scales, heat and charge transport are strongly affected by confinement, interfaces, and structural disorder, often leading to deviations from classical macroscopic models. This talk presents complementary experimental approaches for probing thermoelectric properties at the nanoscale using both contact and contactless characterization techniques. Two methods are addressed: Scanning Thermal Microscopy (SThM), following the approach developed in my group, and thermoreflectance-based techniques. SThM enables local measurements of temperature, thermal conductivity, and thermoelectric voltage with nanometric spatial resolution through direct probe–sample interaction. In this presentation, the capabilities of SThM are illustrated through applications on individual nanowires, allowing the investigation of local heat transport and Seebeck effects at the scale of a single nano-object and its contacts. In parallel, thermoreflectance techniques provide a fully contactless optical approach to quantify thermal and thermoelectric-related properties with high temporal resolution. These methods are demonstrated on nanostructured thin-film materials, where layered architectures and interface engineering play a central role in tailoring thermal transport. By combining these two experimental strategies, we highlight how contact and contactless measurements provide complementary insights into thermoelectric behavior across different length scales. The respective advantages, limitations, and metrological challenges of each technique are discussed, including probe–sample thermal coupling, spatial resolution, sensitivity, and quantitative calibration. This multi-scale experimental framework contributes to a deeper understanding of thermoelectric transport mechanisms in low-dimensional systems and nanostructured materials, and supports the rational design of high-performance thermoelectric devices.
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George FLOUDAS, University of Ioannina, Dept. of Physics, Ioannina, Greece & Max Planck Institute for Polymer Research, Mainz, Germany.
Ion Dynamics during Flow in Nanopores
There has been a growing interest in studying ionic systems (Ionic Liquids, Polymerized Ionic Liquids, Polymer Electrolytes) within nanostructured environments − such as nanoporous materials − in an effort to modulate or even enhance their ionic transport properties. Under confinement, the ion dynamics can be altered because of spatial constraints and surface interactions leading to adsorption. In the first study of the archetypal polymer electrolyte poly(ethylene oxide) (PEO)/LiTFSI during imbibition in nanopores by in situ nanodielectric spectroscopy, it was shown that ion conductivity is largely controlled by PEO adsorption at the pore walls. In PIL/IL mixtures, in situ conductivity measurements during imbibition in nanopores can be used to separate the mixture to its individual components.Here we report on the effects of (i) the geometry of confinement by employing cylindrical vs V-shaped nanopores and (ii) the macromolecular architecture of PILs. Results offer new insights into how molecular architecture and confinement affect ion transport in PILs.
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Kevin NADAUD , Université de Tours, Laboratoire GREMAN, CNRS-UMR7347, France
 
Non-linear electrical characterization of ferroelectric materials and high throughput experiments
Abstract: Thanks to their hysteretic response and the coupling between polarization and strain, ferroelectric materials have an ultra-wide range of applications, such as piezoelectric actuators/sensors, energy storage, memories, neuromorphic devices, or microwave devices. Many of the interesting properties come from the domain structure and the presence of domain walls. Nevertheless, their presence induces strong non-linearities, even for very small excitations, which can make their characterization tricky. In this presentation, I will start with discussing a few of the electrical methods that can be used for the characterization of ferroelectrics, more specifically to probe the domain wall motion and domain switching contributions. I will show that the non-linearities that can, at first glance, complexify the measurements can be turned into a precious tool for a deeper understanding of the material. In the second part, I will describe how those specific characterizations can be coupled with conventional measurements. More specifically, this relies on the use of combinatorial synthesis, high-throughput experiments, and automated data analysis.
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