About the nature of dynamic elastic moduli low-temperature anomaly in cubic AIIbVI crystals doped with 3d-transition metal impurities

The negative paramagnetic contribution to dynamic elastic moduli was detected for the first time in wide band-gap AIIBVI:3d compounds. It was determined as a paramagnetic elastic or briefly paraelastic susceptibility. It was found that these compounds had a linear temperature dependence of inverse paraelastic susceptibility. It was explained by the contribution of diagonal matrix elements of orbit-lattice interaction operators to the dependence of spin-orbit state energy on applied strain by analogy with the Curie contribution to magnetic susceptibility. The inverse paraelastic susceptibility in AIIBVI crystals containing non-Kramers 3d-ions was found to deviate from the linear law reaching the saturation with decreasing temperature. This effect was attributed to the off-diagonal matrix element contribution by analogy with the well-known Van Vleck contribution to magnetic susceptibility of paramagnet. © 2011.