Room temperature ferroelectric properties and leakage current characterics of Bi_2FeMnO_6/SrTiO_3 bilayered thin films by chemical solution deposition

摘要

Bi_2FeMnO_6/SrTiO_3 (BFMO/STO) bilayered thin films were grown on LaNiO_3 (LNO) buffered Si(100) substrate by chemical solution deposition. The structure and surface morphology of the bilayered thin films have been characterized by X-ray diffraction and atomic force microscopy. The All/ BFMO/STO/LNO thin-film capacitor showed well-saturated hysteresis loop at an applied field of 330 kV cm~(-1) with remnant polarization (2P_r) and coercive electric field (2E_c) values of 1.3 μC cm~(-2) and 80kV cm~(-1), respectively. The films show leakage current density in the order of 10~(-5) A cm~(-2) in the whole electric field region. The leakage current depended on the voltage polarity. The Au/BFMO/STO interface forms an Ohmic contact with Au electrode biased negatively. At low electric field, the BFMO/STO/LNO interface forms an Ohmic contact with LNO electrode biased negatively. A further increase of applied electric field, the conduction shows a space-charge-limited-current behavior.