Inducing tunable switching behavior in a single memristor

Non-volatile resistive switching based on complex perovskite oxides have demonstrated an immense potential for future neuromorphic and compact logic applications. The adaptation of a functional oxide to exhibit different resistive switching characteristics is an important step in harnessing the full suite of capabilities that such material system has to offer. Further, an understanding of the underlying phenomena that results in such adaptive characteristics is required. In this study, we show that multiple (threshold and bipolar) resistive switching behaviors can be achieved in a bilayer stack of titanium and selectively chromium-doped strontium titanate. High resolution transmission electron microscopic and electron energy loss spectroscopic compositional and micro/nano-structural analyses reveal that the interfacial oxidation of the titanium layer to Ti2O3 introduces an oxide heterostructure with chromium-doped strontium titanate. The concentration and distribution of oxygen vacancies in the heterostructure controls the switching behaviors, which can be controlled by defining the current compliance during the initial electroforming. The existence of current compliance dependent switching behaviors broadens the scope of applications of such selectively doped functional material for resistive memories by making them versatile thereby rendering the technology adaptable to different applications.