Lattice Vibrations of Mg_xCd_1−xTe Mixed Crystals

Abstract

Infrared and Raman measurements of lattice vibrations in Mg_xCd_1−xTe mixed crystals have been made in the concentration range x=0∼0.6. The modified random-element isodisplacement model has been applied to explain the concentration dependence of long wavelength longitudinal and transverse optic phonon frequencies in the mixed crystal system. From fitting the computed values to the experimental data we have estimated the static dielectric constant ε₀, TO and LO phonons of pure MgTe, and a gap made of Cd in MgTe.