High-Performance Ferroelectric Bi_0.5Na_0.5TiO₃ Single Crystals Grown by Top-Seeded Solution Growth Method under High-Pressure Oxygen Atmosphere

Abstract

Top-seeded solution growth method under high-oxygen-pressure atmosphere has been developed for obtaining high-performance and large-sized single crystals of ferroelectric Bi_0.5Na_0.5TiO₃ (BNT). Crystals grown at 1000 °C at a Po₂ of 0.9 MPa exhibited a well-saturated hysteresis with a remanent polarization of 34 μC/cm² and a coercive field of 22 kV/cm along <100>_cubic. The spontaneous polarization of BNT along <111>_cubic is estimated to be 59 μC/cm² from the measured polarization properties along <100>_cubic of the crystals obtained.

Acknowledgments

We would like to thank Professor Hiroaki Takeda, Tokyo Institute of Technology, for his helpful advice on the TSSG method. This study was partly supported by Grant-in-Aid for Scientific Research on Priority Areas “Novel States of Matter Induced by Frustration” (No. 19052002), Grant-in-Aid for Scientific Research(A) (21246096), the Fundamental R&D Program for Core Technology of Materials funded by the Ministry of Knowledge Economy, Republic of Korea, and Grant-in-Aid for Research Fellows of the Japan Society for the Promotion of Science (No. 08J09794).