Temperature dependence of the collective phonon relaxation time and acoustic damping in Ge and Si

Abstract

In this article, a refined method for the numerical calculation of the collective phonon relaxation time over the entire spectrum of thermal phonon modes using a computer program is suggested. For Si, the temperature dependence of relaxation time calculated using our program shows good agreement with the experimental data reported by Ilisavskii and Sternin (Yu.V. Ilisavskii, V.M. Sternin, Sov. Phys. Solid State 27 (1985) 236) using the ultrasonic attenuation experiments. The temperature dependence of attenuation estimated using these relaxation times shows excellent agreement with most of the available experimental data for both Si and Ge.