Magnetic Field Induced Relaxation Attenuation of Ultrasound by Jahn–Teller Centers: Application to ZnSe:Cr2+

Abstract

The influence of magnetic fields on ultrasonic attenuation caused by relaxation in Jahn–Teller centers is studied using chromium ions as Zn substitute impurities in the ZnSe crystal as an example.
The changes of the position and shape of the relaxation peak with the applied magnetic field induction B were observed in the temperature dependence of the ultrasonic attenuation of the shear waves at the frequency of 29.5 MHz propagating along the [110] axis with the polarization vector parallel to the [1\(\overline{1}\)0] axis. To rationalize the results, a simulation procedure was employed assuming that there are two thermal activation mechanism of relaxation with different relaxation times. One of them emerged with activation energy \(V_0=75\) K that remains unchanged in the magnetic fields, the other occurs with increasing \(V_0\) up to \(V_0=106\) K at \(B=14\) T.