Energy Spectrum and Phonon Excitation Damping in Many‐Component Amorphous Solids

Abstract

AbstractPhonon excitations in many‐component amorphous solids are treated using the Green's function method. The equation for the energy spectrum of phonon excitations is obtained. This equation takes into account the hard core in the interatomic interaction potential, the temperature dependence of phonon frequencies, and their damping, caused by phonon scattering on structure fluctuations. Zeroth approximation is considered in a space with arbitrary dimensionality. In this case it coincides with the quasi‐crystalline one. The explicit expressions for the optic and acoustic modes as well as for the longitudinal and transverse velocity of sound are obtained as example in the two‐component case. In the space of arbitrary dimension the asymptotic of damping is studied for the one‐component system in the long‐wave region. Numerical calculations of the “frequency‐wave vector” dependence are performed for some amorphous metals in the quasi‐crystalline approximation.