Capacitorlike metal/metal oxide/metal structures are widely used as resistive switching cells and are utilized in resistive random access memories. Recently, it has been demonstrated that they also perform well as gas sensors. In this work, we have merged the gas sensing and resistive switching capabilities of the capacitorlike Pt/TiO₂/Pt structures to constitute a simple device which works as a gas-triggered thyristorlike switch and as a gas sensor with a built-in memory.

Resistance switching effects in metal/perovskite contacts based on epitaxial c-axis oriented YBa₂Cu₃O_6+c (YBCO) thin films with different crystallographic orientation have been studied. Three types of Ag/YBCO junctions with the contact restricted to (i) c-axis direction, (ii) ab-plane direction, and (iii) both were designed and fabricated, and their current-voltage characteristics have been measured. The type (i) junctions exhibited conventional bipolar resistance switching behavior, whereas in other two types the low-resistance state was unsteady and their resistance quickly relaxed to the initial high-resistance state. Physical mechanism based on the oxygen diffusion scenario, explaining such behavior, is discussed.