Au nanoparticles as template for defect formation in memristive SrTio3 thin films

Abstract

We investigated the possibility of tuning the local switching properties of memristive crystalline SrTiO3 thin films by inserting nanoscale defect nucleation centers. For that purpose, we employed chemically-synthesized Au nanoparticles deposited on 0.5 wt%-Nb-doped SrTiO3 single crystal substrates as a defect formation template for the subsequent growth of SrTiO3. We studied in detail the resulting microstructure and the local conducting and switching properties of the SrTiO3 thin films. We revealed that the Au nanoparticles floated to the SrTiO3 surface during growth, leaving behind a distorted thin film region in their vicinity. By employing conductive-tip atomic force microscopy, these distorted SrTiO3 regions are identified as sites of preferential resistive switching. These findings can be attributed to the enhanced oxygen exchange reaction at the surface in these defective regions.