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 ( Bi 0.6 Tb 0.3 La 0.1 ) Fe O 3 were grown on Pt ∕ Ti ∕ Si O 2 ∕ 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 filmgrown at a lower oxygen pressure of 0.01 torr 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 annealedthin films show a relatively high resistivity and stable polarization loops with double remnant polarization of about 3 μ C ∕ cm 2 . 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 filmgrown at higher oxygen pressure and the Poole-Frenkel conduction for the thin filmsgrown at lower oxygen pressure.