Leakage current of multiferroic (Bi0.6Tb0.3La0.1)FeO3 thin films grown at various oxygen pressures by pulsed laser deposition and annealing effect

Abstract

Thin films of multiferroic (Bi0.6Tb0.3La0.1)FeO3 were grown on Pt∕Ti∕SiO2∕Si substrate under various oxygen pressures by pulsed laser deposition technique. X-ray diffraction patterns show that the crystallinity of the thin film is improved with decreasing depositing oxygen pressure and the thin film grown at a lower oxygen pressure of 0.01torr exhibits a single perovskite phase with preferred (001) orientation. Leakage current of the as-deposited thin films decreases with decreasing grown oxygen pressure. Significantly, the leakage current of the thin films can be reduced largely by an annealing process at 800°C with flowing oxygen. The annealed thin films show a relatively high resistivity and stable polarization loops with double remnant polarization of about 3μC∕cm2. The conduction properties of the thin films have been well analyzed, and it is indicated that the dominant conduction mechanism is the space-charge-limited conduction for the thin film grown at higher oxygen pressure and the Poole-Frenkel conduction for the thin films grown at lower oxygen pressure.