Polarization and piezoelectric properties of high-quality (Bi,Na)TiO₃ crystals grown by high-oxygen-pressure flux method

Abstract

Crystal growth at a high Po 2 (oxygen pressure) is developed for Bi 0.5 Na 0.5 TiO 3 single crystals based on defect chemistry at high temperatures. Bi 0.5 Na 0.5 TiO 3 crystals grown at Po 2 = 1 MPa show a saturated remanent polarization of 44 µC/cm 2 along [110] cubic , suggesting a spontaneous polarization of 54 µC/cm 2 along [111] cubic (polar direction) of rhombohedral Bi 0.5 Na 0.5 TiO 3. High-Po 2 heat treatments are demonstrated to be suitable for fabricating high-quality and high-performance ferroelectric and piezoelectric devices using Bi 0.5 Na 0.5 TiO 3 crystals