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Glass-like Transport Dominates Ultralow Lattice Thermal Conductivity in Modular Crystalline Bi 4 O 4 SeCl 2

2023; American Chemical Society; Volume: 23; Issue: 20 Linguagem: Inglês

10.1021/acs.nanolett.3c02957

1530-6992

Zhen Tong, Alessandro Pecchia, ChiYung Yam, Traian Dumitrică, Thomas Frauenheim,

Thermal Expansion and Ionic Conductivity

Crystalline Bi4O4SeCl2 exhibits record-low 0.1 W/mK lattice thermal conductivity (κL), but the underlying transport mechanism is not yet understood. Using a theoretical framework which incorporates first-principles anharmonic lattice dynamics into a unified heat transport theory, we compute both the particle-like and glass-like components of κL in crystalline and pellet Bi4O4SeCl2 forms. The model includes intrinsic three- and four-phonon scattering processes and extrinsic defect and extended defect scattering contributing to the phonon lifetime, as well as temperature-dependent interatomic force constants linked to phonon frequency shifts and anharmonicity. Bi4O4SeCl2 displays strongly anisotropic complex crystal behavior with dominant glass-like transport along the cross-plane direction. The uncovered origin of κL underscores an intrinsic approach for designing extremely low κL materials.