Evidence for multifilamentary valence changes in resistive switching SrTiO3 devices detected by transmission X-ray microscopy

Transmission X-ray microscopy is employed to detect nanoscale valence changes in resistive switching SrTiO3 thin film devices. By recording Ti L-edge spectra of samples in different resistive states, we could show that some spots with slightly distorted structure and a small reduction to Ti3+ are already present in the virgin films. In the ON-state, these spots are further reduced to Ti3+ to different degrees while the remaining film persists in the Ti4+ configuration. These observations are consistent with a self-accelerating reduction within pre-reduced extended growth defects. (C) 2013 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.