Origin of the enhanced piezoelectric thermal stability in BiScO3-PbTiO3 single crystals

BiScO 3 -PbTiO 3 single crystals were reported to possess high piezoelectric coefficient of 1200 pC/N and Curie temperature of > 400°C, exhibiting excellent thermal stability of properties up to 350°C. However, the origin of the thermal stability is yet unclear. In this research, high resolution synchrotron-based technique was used to study the temperature driven structural evolution in BiScO 3 -PbTiO 3 system, where two competing symmetries and local distortion were observed, accounting for the high piezoelectric activity. A strong correlation between thermal stability of structure and temperature-dependent properties was established, which will benefit the design of ferroelectric materials with broad temperature usage range.