Resistive hystersis effects in perovskite oxide-based heterostructure junctions

Abstract

The electrical and structural properties of the oxide-based metal/ferroelectric/metal (MFM) junctions are reported. The heterostructures are composed of ultrathin layers of La0.7Ca0.3MnO3 (LCMO) as a metallic layer and BaTiO3 (BTO) as a ferroelectric layer. Junction based devices, having the dimensions of 400×200μm2, have been fabricated upon LCMO/BTO/LCMO heterostructures by photolithography and Ar-ion milling technique. The dc current-voltage (I-V) characteristics of the MFM junctions were carried out. At 300K, the devices showed the linear (I-V) characteristics, whereas at 77K, (I-V) curves exhibited some reproducible switching behaviors with well-defined remnant currents. The resulting resistance modulation is very different from what was already reported in ultrathin ferroelectric layers displaying resistive switching. A model is presented to explain the data.