Scanning transmission X-ray microscopy probe forin situmechanism study of graphene-oxide-based resistive random access memory

Here, anin situprobe for scanning transmission X-ray microscopy (STXM) has been developed and applied to the study of the bipolar resistive switching (BRS) mechanism in an Al/graphene oxide (GO)/Al resistive random access memory (RRAM) device. To performin situSTXM studies at the CK- and OK-edges, both the RRAM junctions and theI0junction were fabricated on a single Si3N4membrane to obtain local XANES spectra at these absorption edges with more delicateI0normalization. Using this probe combined with the synchrotron-based STXM technique, it was possible to observe unique chemical changes involved in the BRS process of the Al/GO/Al RRAM device. Reversible oxidation and reduction of GO induced by the externally applied bias voltages were observed at the OK-edge XANES feature located at 538.2 eV, which strongly supported the oxygen ion drift model that was recently proposed fromex situtransmission electron microscope studies.