Optical properties of CdTe, ZnTe semiconducting compounds and solid solutions on their base in the far infrared region

Behaviour dynamics of long-wave phonons and of principal optical constants of ZnTe, CdTe compounds and Znsub(x)Cdsub(1-x)Te mixed, crystals has been studied. Improved values of optical phonon frequencies in the centre of the Brillouin zone with allowance made for anharmonicity effects are obtained. The principal optical constants of the compounds are determined. This system is shown to possess a new type of the optical phonon frequencies which vary unusually with a composition. The obtained dependencies of oscillator strengths of longitudinal and transverse phonons on the composition of a solid solution system also revealed the anomalous behaviour resulting from the fact that at small x the impurity vibration of zinc atoms is quasi-local (resonance). With x increasing it turns into longitudinal and transverse local vibrations. At x → 1 this longitudinal vibration turns into an impurity longitudinal vibration, whereas the transverse impurity vibration of zinc atoms at x → 1 turns into the fundamental transverse vibration