Elastic constants and calculated lattice vibration frequencies of Mg 2Sn

Abstract

The longitudinal and shear sound velocities of Mg 2Sn in the [100], [110] and [111] directions have been measured between 80 and 300°K by a resonance technique. The elastic constants were computed from these velocities. Lattice vibration frequencies have been calculated for two point ion models and a shell model. Best agreement with the experimental specific heat data was obtained for the shell model, which reproduced quite accurately the sharp minimum in the Debye temperature near 20°K.