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Single-channel or multichannel thermal transport: Effect of higher-order anharmonic corrections on the predicted phonon thermal transport properties of semiconductors
Journal
Physical Review B
ISSN
24699950
Date Issued
2022-07-15
Author(s)
Jain, Ankit
Abstract
The phonon thermal transport properties of eight ternary intermetallic semiconductors are investigated by accounting for higher-order four-phonon scattering, phonon renormalization, and multichannel thermal transport. The commonly used lowest-order theory, which accounts only for three-phonon scattering and without phonon renormalization, fails drastically for the considered materials and underpredicts the thermal conductivity by up to a factor of two. The thermal conductivity decreases for three compounds and increases for five compounds with the application of higher-order corrections owing to a contrasting role of four-phonon scattering and phonon stiffening on the predicted thermal conductivity. Using the higher-order theory, at a temperature of 300 K, the lowest obtained thermal conductivity is 0.31 W/m K for BiCsK2 and three other compounds (SbCsK2, SbRbNa2, and SbRbK2) have thermal conductivities lower than 0.5W/mK via the particlelike phonon transport channel. The contribution from the wavelike coherent transport channel is lower than 0.05 W/m K in all of these ultralow thermal conductivity compounds. The higher-order theory is crucial for the correct description of thermal transport physics, failing which the thermal transport is wrongly characterized as multichannel transport by the lowest-order theory.
Volume
106
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