Dielectric Properties of La Doped-Hexagonal BaTiO_3 Single Crystal Grown by FZ Method

摘要

The oxygen-deficient hexagonal BaTiO_3 shows huge dielectric constant. Because of the oxygen-deficient induced to cliange the valance from Ti~(4+) to Ti~(3+) and formed the charge imbalance in a lattice. However, this dielectric constant is easily disappeared when the oxygen-deficient is compensated. And it is difficult to control the amount of oxygen-deficient in hexagonal BaTiO_3. In this study, the oxygen deficient is substituted by La to keep the charge imbalance. It was successful to retain the huge dielectric constant of La doped hexagonal BaTiO_3. La~(3+) could induce to change the valance from Ti~(4+) to Ti~(3+). And it shows almost the same behavior on the complex plane of Z by an impedance measurement. La doped hexagonal BaTiO_3 has a semiconductive behavior.