Antiferroelectric phase transition in SbSI and SbSeI crystals

This work represents existence of the high temperature antiferroelectric phase transitions in SbSI, SbSeI and BiSeI crystals. The antiferrolectric phase transition is found by a measured capacitance change at a frequency of 1 kHz for the SbSI and SbSeI crystals grown by the Bridgman–Stockbarger technique in the temperature range of 270–440 K. Therefore, SbSI has three phases: ferroelectric ( T < 295 K ), antiferroelectric ( 295 < T < 410 K ) and paraelectric ( T > 410 K ). SbSeI has two phases: antiferroelectric ( T < 410 K ) and paraelectric ( T > 410 K ). The antiferroelectric phase transition is of an intermediate type between displacive and order–disorder types.