Electrical Characteristics and Microstructures of Sm₂O₃-Doped Bi₄Ti₃O₁₂ Ceramics

We investigate the electrical properties of Sm-doped Bi_4-xSm_xTi₃O₁₂ (BST) ceramics prepared by a conventional electroceramic technique. The x-ray diffraction analysis reveals the Bi-layered perovskite structure in all samples. The SEM micrographs show randomly oriented and plate-like morphology. For the samples with x=0.4 and 1.0, the current--voltage characteristics exhibit negative differential resistance behaviour and the P--V hysteresis loops are characterized by large leakage current, whereas for the samples with x=0.6 and 0.8, the current--voltage characteristics show simple ohmic behaviour and the P--V hysteresis loops are of the saturated and undistorted hysteresis. The remanent polarization and coercive field of the BST ceramic with x=0.8 are above 32μC/cm² and 70kV/cm, respectively.