Decay processes of long-lived phonons in 6H-SiC

D A Pshenay-Severin; R B Adamov; M Ya Vinnichenko; M D Moldavskaya; V A Shalygin

doi:10.1088/1361-648X/acbb4b

Decay processes of long-lived phonons in 6H-SiC

J Phys Condens Matter. 2023 Mar 1;35(17). doi: 10.1088/1361-648X/acbb4b.

Authors

D A Pshenay-Severin^{1

2}, R B Adamov¹, M Ya Vinnichenko¹, M D Moldavskaya¹, V A Shalygin¹

Affiliations

¹ Institute of Electronics and Telecommunications, Peter the Great St. Petersburg Polytechnic University, 29 Polytechnicheskaya str., St. Petersburg 195251, Russia.
² Ioffe Institute, 26 Politechnicheskaya str., St. Petersburg 194021, Russia.

PMID: 36764000
DOI: 10.1088/1361-648X/acbb4b

Abstract

Temperature evolution of the high-resolution far-infrared transmission spectra of 6H-SiC single crystal slab is experimentally examined in a temperature range of 5-320 K. Temperature dependences of the phonon lifetimes for long-lived phonons, namely the IR active folded transverse acoustic (FTA) phonon doublet, are determined. These dependences are interpreted in the framework of a theoretical model developed using first principle anharmonic lattice dynamics. It is shown that three-phonon anharmonic processes dominate in the FTA phonon decay at temperatures above 160 K resulting in a rapid decrease of the phonon lifetimes with increasing temperature. Contribution of four-phonon anharmonic processes is negligibly small at temperatures below 320 K.

Keywords: 6H-SiC; anharmonic decay processes; far-infrared transmission; folded transverse acoustic phonons; phonon decay; phonon lifetimes.