Variation of leakage mechanism and potential barrier in La and Ru co-doped BiFeO3 thin films

Epitaxial c-axis-oriented La and Ru co-doped BiFeO3 (BLFRO) films are deposited on (0 0 1)-orientated Nb–SrTiO3 substrates by pulsed laser deposition. The phase and domain structures, ferroelectric and dielectric properties are characterized. The leakage current mechanisms of the BLFRO film are investigated at various temperatures. Poole–Frenkel (PF) and space-charge-limited current (SCLC) mechanisms are found to be dominant at high and low electric fields, respectively. PF emission is the dominant mechanism at high temperatures, whereas SCLC is dominant at low temperatures. The potential barriers at the electrode interfaces are estimated to be approximately 0.8 eV for the BLFRO film.