title: Interfacial Redox Reactions Associated Ionic Transport in Oxide-Based Memories.
abstract: As an alternative to transistor-based flash memories, redox reactions mediated resistive switches are considered as the most promising next-generation nonvolatile memories that combine the advantages of a simple metal/solid electrolyte (insulator)/metal structure, high scalability, low power consumption, and fast processing. For cation-based memories, the unavailability of in-built mobile cations in many solid electrolytes/insulators (e.g., Ta2O5, SiO2, etc.) instigates the essential role of absorbed water in films to keep electroneutrality for redox reactions at counter electrodes. Herein, we demonstrate electrochemical characteristics (oxidation/reduction reactions) of active electrodes (Ag and Cu) at the electrode/electrolyte interface and their subsequent ions transportation in Fe3O4film by means of cyclic voltammetry measurements. By posing positive potentials on Ag/Cu active electrodes, Ag preferentially oxidized to Ag+, while Cu prefers to oxidize into Cu2+first, followed by Cu/Cu+oxidation. By sweeping the reverse potential, the oxidized ions can be subsequently reduced at the counter electrode. The results presented here provide a detailed understanding of the resistive switching phenomenon in Fe3O4-based memory cells. The results were further discussed on the basis of electrochemically assisted cations diffusions in the presence of absorbed surface water molecules in the film.
authors.affiliation: School of Materials Science and Engineering, University of New South Wales , Sydney, NSW 2052, Australia.
authors.forename: Adnan
authors.identifier: http://orcid.org/0000-0003-3453-4214
authors.initials: A
authors.lastname: Younis
authors.affiliation: School of Materials Science and Engineering, University of New South Wales , Sydney, NSW 2052, Australia.
authors.forename: Dewei
authors.initials: D
authors.lastname: Chu
authors.affiliation: Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH) , 790-784 Pohang, Republic of Korea.
authors.forename: Abdul Hadi
authors.initials: AH
authors.lastname: Shah
authors.affiliation: School of Materials Science and Engineering, University of New South Wales , Sydney, NSW 2052, Australia.
authors.forename: Haiwei
authors.initials: H
authors.lastname: Du
authors.affiliation: School of Materials Science and Engineering, University of New South Wales , Sydney, NSW 2052, Australia.
authors.forename: Sean
authors.initials: S
authors.lastname: Li
keywords: absorbed moisture; electrochemical metallization; redox process; resistive switching; thin films