Studies on Leakage Mechanisms and Electrical Properties of Doped BiFeO[sub 3] Films

Abstract

The effects of La and/or Ti doping on crystallization, surface morphology, and electric properties of bismuth ferrite (BFO) films were investigated. All films consisted of single perovskite phase without a second phase. Ti-doping (BFT) does not have significant effects on leakage and polarization-electric field (P-E) loop. La-doping (BLF) improves leakage but degrades ferroelectric properties. In contrast, (La, Ti)-co-doping (BLFT) not only improves the leakage, but also decreases the relaxation gap of P-E loop. The determined leakage mechanisms of BFO, BFT, BLF, and BLFT are space charge-limited conduction (SCLC) with deep traps, grain boundary-limited conduction (GBLC), Poole-Frenkel, and SCLC with both shallow and deep traps, respectively.