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Place CentraleSupélec, Amphi sc.046 (Peugeot), Bouygues
Vibrations and Heat Transfers in Amorphous Materials and in Glass-Ceramics
Amorphous materials have high heat capacity but low thermal conductivity compared to crystals with the same composition. The understanding of these properties is based on the study of acoustic attenuation and more generally on the specific vibrational properties of glasses, which are reminiscent in a more general way of those of heterogeneous materials such as polycrystals. After a general description of the vibrational eigenmodes in disordered materials, we will show the link between the dynamics of vibrational wave packets and the expression of thermal conductivity at the atomic scale. We will then discuss the different acoustic attenuation mechanisms and their expression at different scales: from the atomic scale to the continuous scale. Finally, we will focus on the effect of crystal/amorphous interfaces on the thermal properties of nanostructured materials such as glass-ceramics. We will show how the presence of amorphous parts reinforces the diffusive contribution to heat transport, and allows controlling the temperature dependence of the thermal conductivity.
[1] Y. Beltukov, D. A. Parshin, V.M. Giordano and A. Tanguy Physical Review E 98 023005 (2018): Propagative and diffusive regimes of acoustic damping in bulk amorphous material.
[2] P. Desmarchelier, A. Carré, K. Termentzidis and A. Tanguy Nanomaterials 11, 1982 (2021): Heat Transport in Nanocomposite: The Role of the Shape and Interconnection of Nanoinclusions
[3] H. Luo, V.M. Giordano, A. Gravouil and A. Tanguy Journal of Non-Crystalline Solids 583, 121472 (2022): A continuum model reproducing the multiple frequency crossovers in acoustic attenuation in glasses
[4] M. Hadi et al. Nature Communications 14, 1317 (2024): The effect of echoes interference on phonon attenuation in a nanophononic membrane