Elastic Moduli in Cadmium Selenide Doped with Chromium

Temperature dependence of elastic moduli (C₁₁ − C₁₂ ) / 2 , C₃₃ , and C₄₄, the latter for the piezo-active and non-piezo-active versions, have been measured in the interval of 4 - 180 K at 28 - 262 MHz in a CdSe: Cr²⁺ crystal. Anomalies below 40 K have been found for all the moduli, except C₃₃ . The interpretation of the results has been carried out involving the Jahn-Teller effect and relaxation between the equivalent distortions of the tetrahedral CrSe₄ centers.