Enhanced piezoelectricity of barium titanate single crystals with engineered domain configuration

Engineered domain configurations with different domain sizes were induced in [111]c oriented tetragonal barium titanate BaTiO3 single crystals, and their piezoelectric properties investigated as a function of domain size. Prior to this study, the dependence of domain configuration on temperature and electric field E was investigated using polarised light microscopy to establish the optimum conditions for domain size control. As a result, above the Curie temperature Tc of 132.2°C, when E greater than 6 kV cm−1 was applied along the [111]c direction, an engineered domain configuration with fine domain structure appeared. Moreover, it was also found that this fine domain structure was still stable at room temperature in the absence of electric field. Finally, the piezoelectric properties were measured using 31 resonators with three domain sizes, and it was found that piezoelectric properties such as d31 and k31 increased significantly with decreasing domain size.