Raman scattering study of pressure-induced phase transitions in AIIB2IIIC4VI defect chalcopyrites and spinels

Abstract

AIIB2IIIC4VI defect chalcopyrites (DC) and spinels were investigated by Raman scattering spectroscopy under hydrostatic pressure up to 20 GPa. All these compounds were found to undergo a phase transition to a Raman inactive defect NaCl-type structure. The phase transition is reversible for spinels and irreversible for DC. From the analysis of the pressure behavior of Raman-active modes, it was concluded that the phase transition from spinel to NaCl-type structure is direct in MnIn2S4 and CdIn2S4, while it occurs via an intermediate LiVO2-type NaCl superstructure in MgIn2S4. The observed differences in the pressures and the paths of the pressure-induced phase transitions in AIIB2IIIC4VI compounds are discussed.