Enhanced Piezoelectric Properties of Piezoelectric Single Crystals by Domain Engineering

抄録

Various engineered domain configurations were induced into barium titanate (BaTiO₃) single crystals, and their piezoelectric properties were investigated as a function of (1) the crystal structure, (2) the crystallographic orientation and (3) the domain size. As a result, the orthorhombic mm2 BaTiO₃ crystals showed the highest piezoelectric properties among three kinds of BaTiO₃ crystals such as tetragonal 4mm, orthorhombic mm2 and rhombohedral 3m phases. On the other hand, the [001]_c oriented BaTiO₃ crystals always exhibited the larger piezoelectric properties than the [111]_c oriented BaTiO₃ crystals. Moreover, the domain size dependence on the piezoelectric properties was discussed, and this result revealed that the piezoelectric property was strongly dependent on the domain size, i.e., the piezoelectric properties significantly increased with decreasing domain size. On the basis of the above results, the most suitable engineered domain configuration was proposed for the high-strain high-coupling piezoelectric application.