Strong low-energy rattling modes enabled liquid-like ultralow thermal conductivity in a well-ordered solid.

ABSTRACT: Crystalline solids exhibiting inherently low lattice thermal conductivity (κ _L) are of great importance in applications such as thermoelectrics and thermal barrier coatings. However, κ _L cannot be arbitrarily low and is limited by the minimum thermal conductivity related to phonon dispersions. In this work, we report the liquid-like thermal transport in a well-ordered crystalline CsAg₅Te₃, which exhibits an extremely low κ _L value of ∼0.18 Wm^-1K^-1. On the basis of first-principles calculations and inelastic neutron scattering measurements, we find that there are lots of low-lying optical phonon modes at ∼3.1 meV hosting the avoided-crossing behavior with acoustic phonons. These strongly locali

SUBMITTER: Liu PF 

PROVIDER: S-EPMC11562843 | biostudies-literature | 2024 Dec

REPOSITORIES: biostudies-literature