Structural correlation of GeTeSeGa system by XRD and far-infrared spectroscopy

The structural properties of quaternary Ge${}_{10}$Te${}_{80}$Se${}_{10-x}$Ga${}_x$ (x = 0 to 10) glassy alloy have been studied with XRD (X-ray diffraction) and FTIR (Fourier transform infrared) spectroscopy. The position of FSDP (first sharp diffraction peak) (2θ) and its FWHM (full width half maxima) have been utilized to estimate the local structure parameters of FSDP like repeating distance y and structural correlation length (L). The far-infrared (IR) transmission spectra of Ge${}_{10}$Te${}_{80}$Se${}_{10-x}$Ga${}_x$ (x = 0, 2, 4, 6, 8, 10) have been analysed in the range 30–300 cm${}^{-1}$ to study the formation of bonds using chain crossing model, random covalent network model and chemical bond approach. The theoretical calculations have been executed for bond energies, force constants, wave number, etc., for probable bonds, and the results justify the experimental values. The present study contributes to the understanding of the composition-dependent structural property relationship of chalcogenide glasses.