title: Scanning transmission X-ray microscopy probe for in situ mechanism study of graphene-oxide-based resistive random access memory.
abstract: Here, an in situ probe 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 perform in situ STXM studies at the C K- and O K-edges, both the RRAM junctions and the I0 junction were fabricated on a single Si3N4 membrane to obtain local XANES spectra at these absorption edges with more delicate I0 normalization. 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 O K-edge XANES feature located at 538.2 eV, which strongly supported the oxygen ion drift model that was recently proposed from ex situ transmission electron microscope studies.
authors.affiliation: Department of Chemistry, Hanyang University, 222 Wangsimniro, Seoul 133-791, Republic of Korea.
authors.forename: Hyun Woo
authors.initials: HW
authors.lastname: Nho
authors.affiliation: Department of Chemistry, Hanyang University, 222 Wangsimniro, Seoul 133-791, Republic of Korea.
authors.forename: Jong Yun
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Canadian Light Source Inc., University of Saskatchewan, 44 Innovation Boulevard, Saskatoon, Saskatchewan, Canada S7N 2V3.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.affiliation: Pohang Accelerator Laboratory and Department of Physics, Pohang University of Science and Technology, 80 Jigokro-127-beongil, Pohang, Gyeongbuk 790-834, Republic of Korea.
authors.forename: Hyun-Joon
authors.initials: HJ
authors.lastname: Shin
authors.affiliation: Department of Electrical Engineering and Graphene Research Center, KAIST, 291 Daehak-ro, Daejeon 305-701, Republic of Korea.
authors.forename: Sung-Yool
authors.initials: SY
authors.lastname: Choi
authors.affiliation: Department of Chemistry, Hanyang University, 222 Wangsimniro, Seoul 133-791, Republic of Korea.
authors.forename: Tae Hyun
authors.initials: TH
authors.lastname: Yoon
mesh_terms: D006108:Graphite / Q000737:chemistry*; D008853:Microscopy / Q000379:methods*; D015335:Molecular Probes; D010087:Oxides / Q000737:chemistry*; D056928:X-Ray Absorption Spectroscopy
chemical_list: D015335:Molecular Probes; D010087:Oxides; D006108:Graphite
keywords: GO-RRAM; STXM; bipolar resistive switching mechanism; graphene oxide; in situ; oxygen ion drift model; scanning transmission X-ray microscopy