Mechanisms of resistive switching in BiFeO3 thin films modulated by bottom electrode

BiFeO3 thin films were fabricated by pulsed laser deposition on Nb–SrTiO3 (0 0 1), La2/3Sr1/3MnO3/SrTiO3 (0 0 1), and SrRuO3/SrTiO3 (0 0 1) electrode surfaces. All films grew epitaxially along the substrates and were fully strained. The current–voltage curves of the structures revealed that the current level depended on the barrier height at the ferroelectric/bottom electrode interface. Resistive switching behavior was observed in the BiFeO3 films grown on all electrodes, which was rationalized in terms of conductive filaments and the variation of the Schottky barrier at the ferroelectric/electrode interfaces due to ferroelectric polarization. The conductive filament model and modulation of the Schottky barriers at film/electrode interfaces due to ferroelectric polarization applied to BiFeO3 films on SrRuO3 and La2/3Sr1/3MnO3 electrodes, respectively, while a combination of these two mechanisms was suggested to be responsible for the observed resistive switching of BiFeO3 film on Nb–SrTiO3.