Specific features of the absorption and phase velocity of ultrasound near the low-temperature phase transition induced by 3d impurities in a ZnSe crystal

Abstract

This paper reports on the results of temperature investigations into the absorption and velocity of ultrasound in ZnSe: Ni and ZnSe: Cr crystals in the frequency range 33-268 MHz. The frequency dependence of the absorption at the maximum is analyzed, and the energy of the excited state of the Ni2+ ions is calculated. The dynamic contribution to the effective elastic modulus is determined, and the results obtained are used to construct the temperature dependences of the relaxed and unrelaxed elastic moduli. © 2005 Pleiades Publishing, Inc.