Characteristics of modification of vibrational spectra of semiconductor-semimetal, CdTe-HgTe alloys. Lattice modes of Cd-Te and Hg-Te vibrations

The parameters of lattice oscillators, deduced from dispersion and Kramers-Kronig analyses of the lattice reflection spectra of Cd 1−x Hg x Te alloys, are considered on the basis of a model of the structure of an alloy with five Cd(4−n)Hg(n)Te (n=0,1,2,3,4) basic cells consisting of cations distributed tetrahedrally around a shared Te anion. Each basis cell is characterized by its own modes of Cd-Te and Hg-Te vibrations. The lattice reflection spectra of all the Cd 1−x Hg x Te alloys are approximated by the properties of four Cd-Te vibrational modes and four Hg-Te vibrational modes in five Cd(4−n)Hg(n)Te basis cells