RWTH Aachen University, Germany
Title: Resistive switching in highly disordered thin oxide films
Biography: Manfred Martin
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, proving that oxygen ion mobility causes memristive behavior. The shape of the hysteresis I-V curves is tunable by the bias history, 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. Further examples will be discussed
Recent Publications :
Liu M, Leichtweiß T, Janek J, Martin M (2013) In-situ structural investigation of non-stoichiometric HfO2-x films using quick-scanning extended X-ray absorption fine structure, Thin Solid Films 539:60-64.
2. Leichtweiß T, Henning RA, Koettgen J, Schmidt RM, Holländer B, Martin M, Wuttig M, Janek J (2014) Amorphous and Highly Nonstoichiometric Titania (TiOx) Thin Films close to Metal-like Conductivity, Mater. Chem. A 2:6631-6640.
3. Aoki Y, Wiemann C, Feyer V, Kim HS, Schneider CM, Yoo HI, Martin M (2014) Bulk mixed ion electron conduction in amorphous gallium oxide causes memristive behaviour, Nat.Commun. 5:3473 doi: 10.1038/ncomms4473.
4. Kura C, Aoki Y, Tsuji E, Habazaki H, Martin M (2016) Fabrication of a resistive switching gallium oxide thin film with a tailored gallium valence state and oxygen deficiency by rf cosputtering process, RSC Advances 6:8964-8070.