Vibrational Spectra of TlInS2, TlIn0.95Ga0.05S2, and TlIn(S0.8Se0.2)2 Crystals in the Vicinity of Phase Transitions

Abstract
Structural phase transitions in TlInS2, TlIn0.95Ga0.05S2, and TlIn(S0.8Se0.2)2 crystals are investigated by infrared reflection spectroscopy. An attempt is made to affect the parameters of the vibrational spectrum and the phase transition temperatures of a TlInS2 crystal by introducing impurities into it in order to obtain additional data necessary to construct phase transitions mechanisms.