Unraveling Convoluted Structural Transitions in SnTe at High Pressure

Abstract

The longstanding uncertainty in high-pressure structural evolution of SnTe has greatly impeded the understanding of its complex electronic properties. Here we unravel the convoluted high-pressure phase transitions of SnTe using angle-dispersive synchrotron X-ray diffraction combined with first-principles structural search. We identify three coexisting intermediate phases of Pnma, Cmcm, and GeS type structure and establish the corresponding phase boundaries. We further unveil the intricate pressure-driven evolution of the energetics, kinetics, and lattice dynamics to elucidate its distinct phase-transition mechanisms. These findings resolve structures of SnTe, which have broad implications for other IV–VI semiconductors that likely harbor similar novel high-pressure phases.