title: Bulk mixed ion electron conduction in amorphous gallium oxide causes memristive behaviour.
abstract: In thin films of mixed ionic electronic conductors sandwiched by two ion-blocking electrodes, the homogeneous migration of ions and their polarization will modify the electronic carrier distribution across the conductor, thereby enabling homogeneous resistive switching. Here we report non-filamentary memristive switching based on the bulk oxide ion conductivity of amorphous GaOx (x~1.1) thin films. We directly observe reversible enrichment and depletion of oxygen ions at the blocking electrodes responding to the bias polarity by using photoemission and transmission electron microscopies, thus proving that oxygen ion mobility at room temperature causes memristive behaviour. The shape of the hysteresis I-V curves is tunable by the bias history, ranging from narrow counter figure-eight loops to wide hysteresis, triangle loops as found in the mathematically derived memristor model. This dynamical behaviour can be attributed to the coupled ion drift and diffusion motion and the oxygen concentration profile acting as a state function of the memristor.
authors.affiliation: 1] Institute of Physical Chemistry, RWTH Aachen University and JARA-FIT, 52056 Aachen, Germany [2].
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Aoki
authors.affiliation: Peter Grünberg Institute (PGI-6) and JARA-FIT, Research Centre Jülich, 52425 Jülich, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Wiemann
authors.affiliation: Peter Grünberg Institute (PGI-6) and JARA-FIT, Research Centre Jülich, 52425 Jülich, Germany.
authors.forename: Vitaliy
authors.initials: V
authors.lastname: Feyer
authors.affiliation: Department of Materials Science and Engineering, Seoul National University, Seoul 151-744, Korea.
authors.forename: Hong-Seok
authors.initials: HS
authors.lastname: Kim
authors.affiliation: 1] Peter Grünberg Institute (PGI-6) and JARA-FIT, Research Centre Jülich, 52425 Jülich, Germany [2] Fakultät für Physik and Center for Nanointegration Duisburg-Essen (CENIDE), Universität Duisburg-Essen, D-47048 Duisburg, Germany.
authors.forename: Claus Michael
authors.initials: CM
authors.lastname: Schneider
authors.affiliation: Department of Materials Science and Engineering, Seoul National University, Seoul 151-744, Korea.
authors.forename: Han
authors.initials: H
authors.lastname: Ill-Yoo
authors.affiliation: 1] Institute of Physical Chemistry, RWTH Aachen University and JARA-FIT, 52056 Aachen, Germany [2] Department of Materials Science and Engineering, Seoul National University, Seoul 151-744, Korea [3].
authors.forename: Manfred
authors.initials: M
authors.lastname: Martin