Resistance Switching Behavior in Rectangle-Nano-Pattern SrTiO₃ Induced by Simple Annealing

The tunability of semi-conductivity in SrTiO₃ single crystal substrates has been realized by a simple encapsulated annealing method under argon atmosphere. This high temperature annealing-induced property changes are characterized by the transmission spectra, scanning electron microscopy (SEM) and synchrotron-based X-ray absorption (XAS). We find the optical property is strongly influenced by the annealing time (with significant decrease of transmittance). A sub gap absorption at ~427 nm is detected which is attributed to the introduction of oxygen vacancy. Interestingly, in the SEM images, annealing-induced regularly rectangle nano-patterns are directly observed which is contributed to the conducting filaments. The XAS of O K-edge spectra shows the changes of electronic structure by annealing. Very importantly, resistance switching response is displayed in the annealed SrTiO₃ single crystal. This suggests a possible simplified route to tune the conductivity of SrTiO₃ and further develop novel resistance switching materials.