Berlin 2024 – wissenschaftliches Programm

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KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur

KFM 33: Focus Session: (Multi-)Ferroic States V

KFM 33.2: Vortrag

Freitag, 22. März 2024, 09:50–10:10, EMH 225

Reversible thermal conductivity switching in barium titanate ceramics — •Lucile Féger, Nassima Radouane, Fabien Giovannelli, Julien Bustillo, Nathalie Poirot, Guillaume F. Nataf, and Isabelle Monot-Laffez — GREMAN UMR7347, CNRS, University of Tours, INSA Centre Val de Loire, 37000 Tours, France

Control of charge flows led to the invention of the transistor and all related electronic devices of our daily life. In contrast, manipulating heat flows is still a challenge and this trend is driven by the constant pursuit of novel properties, efficiency, and functionality in technological applications. Yet, heat management is essential in electronic circuits and may lead to the development of a new paradigm of logic (phononics) [1]. Ferroelectric materials are a promising class of materials to design thermal switches, due to the strong dependence of their properties to an applied electric field. Here we investigate the evolution under an electric field of the thermal conductivity of barium titanate. For this purpose, we adapted a laser flash system to be able to apply a voltage in-situ. We then measured at different temperatures the thermal conductivity of ceramics of barium titanate with different grain sizes: 0.5, 5, 50 and 100 micrometers. We show reversible changes in thermal conductivity under the application of an electric field in-situ, which are compared to measurements where the electric field is applied ex-situ [2]. We discuss our results based on changes in polarization and domain structures induced by the electric field. [1] Li, N. et al. Reviews of Modern Physics, 84 (2012). [2] Lin, Y. et al. ACS Applied Materials & Interfaces,14 (2022).

Keywords: ferroelectricity; domains; thermal conductivity; thermal switch