Phase transition temperature of the α-In2Se3 single crystal

Abstract The variation of phase transition temperature was observed when the heating-cooling cycle of the stoichiometric α-In2Se3 single crystals was repeated under the vacuum of 4 × 10−5 torr. The critical temperature of α → β-phase transition decreased but the critical temperature of β → α-phase transition increased as the number of heating-cooling cycle increased. This phase transition temperature shift control can be understood when we consider the fact that the stoichiometric α-In2Se3 single crystal changes to the In-excess α-In2Se3 single crystal due to the evaporation of selenium atoms when the sample was in heating cycle.