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FM: Fachverband Funktionsmaterialien
FM 4: Focus Session: (Anti)ferroic states – Non-conventional states I
FM 4.5: Vortrag
Montag, 9. März 2026, 16:15–16:30, BEY/0138
Time-domain thermoreflectance for monitoring thermal conductivity switching in ferroelectric thin film — •Wasim Akram1, Stefan Dilhaire2, Thomas Maroutian3, and Guillaume F. Nataf1 — 1GREMAN UMR7347, CNRS, Université de Tours, France — 2CNRS-LOMA/UMR5798, Université de Bordeaux, France — 3C2N, CNRS, Université Paris-Saclay, France
Ferroelectric materials that exhibit thermal conductivity switching under external stimuli could serve as promising candidates for thermal conductivity switches [1,2]. To integrate these switches into miniaturized devices, nanoscale ferroelectric films are essential. In this work, we aim to study ferroelectric thin films and propose to manipulate their thermal conductivity by applying an electric field. To monitor the thermal conductivity, we employ time-domain thermoreflectance (TDTR). In TDTR, the sample surface is periodically heated with a far-infrared pump laser through a metallic transducer, and the resulting thermoreflectance response is probed using a delayed probe laser. The probe reflectivity change is directly related to the temperature evolution at the sample surface. The analysis relies on multilayer heat-transfer models that incorporate the substrate, film, and transducer. However, modelling is sensitive to several experimental constraints, including non-uniform interface properties and interfacial thermal resistance. Here, we address these challenges by optimizing both data-acquisition and sample-preparation methods. We use a home-made software based on Thermal Quadrupole model to fit the signal received by the photodetector [3]. Additionally, we propose to apply an electric field to ferroelectric films to modulate their domain structures, with the goal of achieving multiple fold switching of thermal conductivity. This approach could pave the way toward a device-compatible ferroelectric thermal conductivity switch. [1] Ihlefeld et al. Nano Letters 15 (3), 1791-1795 (2015). [2] Nataf et al. Nature Reviews Materials 9, 530 (2024). [3] Dilhaire et al. J. Appl. Phys. 110, 114314 (2011).
Keywords: Ferroelectrics; Thermal-switching; Phononics; TDTR; Electrothermal