Micro-Spectroscopy on resistive switching Fe:SrTiO₃ thin films
SONDERTERMIN AM MITTWOCH: Annemarie Köhl (Peter-Grünberg Institut 7, Research Center Jülich)

The effect of resistive switching in transition metal oxides is a currently very active field due to the possible applications for future non-volatile memory applications. The term “resistive switching” is thereby used to describe a non-volatile and reversible switching of the electrical resistance by an external voltage stimulus. Although there exists considerable experimental evidence that resistive switching in oxides can be explained by nanoscale redox reactions, the microscopic details are only rarely understood. In this project spatially resolved spectroscopy is employed to directly monitor the redox-process during resistive switching in the valence change material SrTiO₃ .

Epitaxial Fe-doped SrTiO₃ thin films were grown on conducting, single-crystalline Nb:SrTiO₃ substrates by pulsed laser deposition. After an initial forming sweep bipolar resistive switching is enabled and several pads were programmed to different resistive states. After removal of the top electrode spatially resolved photoemission and absorption experiments (XPS/XAS) are performed in a photoemission electron microscope (PEEM). In this way, changes in the electronic structure and chemical compositions induced by the resistive switching process can be revealed.