Compositional Dependence of Optical Modes Frequencies in TlGa_xIn_{1-x}S_2 Layered Mixed Crystals (0 ≤ x ≤ 1)

Abstract

The infrared transmittance and Raman scattering spectra in TlGaxIn1−xS2 (0 ≤ x ≤ 1) layered mixed crystals grown by the Bridgman method were studied in the frequency ranges of 4002000 and 250400 cm −1 , respectively. The bands observed at room temperature in IR transmittance spectra of TlGaxIn1−xS2 were interpreted in terms of multiphonon absorption processes. The dependences of the frequencies of IR-and Raman-active modes on the composition of TlGaxIn1−xS2 mixed crystals were also established. The structural characterization of the mixed crystals was investigated by means of X-ray diraction measurements and compositional dependence of lattice parameters was revealed.