We present the O2-blowing method for the growth of high-quality single crystals of Bi-based perovskite ferroelectrics, in which O2 gas is directly introduced inside crucibles during crystal growth. The O2-blowing method is demonstrated to be effective for enhancing polarization and piezoelectric properties as well as reducing leakage current for (Bi,Na)TiO3-BaTiO3 crystals. The superior properties are suggested to originate from the reduced reorientation of non-180° domains. Ab initio calculations suggest that the interaction between spontaneous polarization and defect dipole composed of Bi vacancy and O vacancy is the origin of the reorientation of non-180° domains.
2008 The Ceramic Society of Japan