Features of the percolation scheme of transformation of the vibrational spectrum with varying alloy composition for Cd(TeSe) and (CdZn)Te alloys with soft bonds

An interpretation of the lattice vibration spectra of mixed II–VI crystals Cd(Te,Se) and (Cd,Zn)Te within the percolation scheme (1-bond $\to$ 2-modes) of transformation of the vibrational spectrum with varying alloy composition is presented. For two-mode alloy systems, the higher-frequency mode is split into two. For Cd(Te,Se) and (Cd,Zn)Te alloys, CdSe- and ZnTe-like vibrations are characterized by percolation doublets with a split of $\delta\approx$ 8 and 4 cm$^{-1}$, respectively. For these II–VI alloys with soft bonds, the distributions of oscillator strengths between percolation doublet modes differ from the model representation originally proposed for chalcogenides (Zn,Be)VI with high contrast in the bond stiffness of binary alloy components.