Variation of leakage current mechanisms by ion substitution in BiFeO3 thin films

Pure BiFeO3 (BFO) and 3, 5, and 7 at. % Mn-substituted BFO (BFMO) films were formed by chemical solution deposition with a crystallization temperature of similar to 550 degrees C. The leakage current density in a BFO film was found to be subject to space-charge-limited conduction, instead of Poole-Frenkel emission. Moreover, the serious transient effect from the traps was observed, indicating the density of trap states is relatively high in the BFO film. On the contrary, the leakage currents in BFMO films were found to be subject to trap-free Ohmic conduction. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3231073]