Abstract
The room-temperature resistivity of La-doped BaTiO3 increases with the increased Mn content. Some of the doped Mn ions will segregate at the grain boundaries and behave as acceptor levels. Thus, Mn will exihibit a grain growth inhibition effect which results in the increase of grain boundaries. Then, the surface charge density (N s) will be increased by the little doped Mn ions and result in a decreased effective donor concentration (N eff) and an enhanced barrier height at the grain boundaries. Thus, the semiconductivity of La-doped BaTiO3 is decreased by Mn addition.