Reproducible low-voltage resistive switching in a low-initial-resistance Pr0.7Ca0.3MnO3 junction

Current-voltage (I-V) characteristics are investigated in a low-initial-resistance Ag/Pr0.7Ca0.3MnO3/Pt sandwich structure. It is found that the junction can show stable low and high resistance states in +/- 0.3V voltage sweeping cycles. The set and reset voltage values are, respectively, +0.1V and -0.2V, which are very low as compared with those reported previously. Furthermore, the I-V curves in both resistance states exhibit rather linear behaviour, without any signature of metal/insulator interface effects. This implies that the Schottky interface mechanism might not be an indispensable factor for the colossal electroresistance effect. The origin of low switching voltages is attributed to the reduced effective distance for electric field action due to the sufficient oxygen content of the PCMO layer. The underlying physics is discussed in terms of the filament network model together with the field-induced oxygen vacancy motion model.