Characteristics of modification of vibrational spectra of semiconductor-semimetal CdTe-HgTe alloys. Two-mode approximation

The lattice reflection spectra of Cd 1−x Hg x Te alloys are analyzed in the two-mode approximation for the vibrational spectrum of quasibinary alloys in terms of CdTe- and HgTe-like vibrations. The composition dependences of frequencies of the TO and LO modes of CdTe-like and HgTe-like vibrations are obtained at temperatures 25, 85, and 300 K. A comparison is made of the information derived from the two-mode and quasimolecular approximations