title: Resistive Switching Mechanisms on TaOx and SrRuO3 Thin-Film Surfaces Probed by Scanning Tunneling Microscopy.
abstract: The local electronic properties of tantalum oxide (TaOx, 2 ≤ x ≤ 2.5) and strontium ruthenate (SrRuO3) thin-film surfaces were studied under the influence of electric fields induced by a scanning tunneling microscope (STM) tip. The switching between different redox states in both oxides is achieved without the need for physical electrical contact by controlling the magnitude and polarity of the applied voltage between the STM tip and the sample surface. We demonstrate for TaOx films that two switching mechanisms operate. Reduced tantalum oxide shows resistive switching due to the formation of metallic Ta, but partial oxidation of the samples changes the switching mechanism to one mediated mainly by oxygen vacancies. For SrRuO3, we found that the switching mechanism depends on the polarity of the applied voltage and involves formation, annihilation, and migration of oxygen vacancies. Although TaOx and SrRuO3 differ significantly in their electronic and structural properties, the resistive switching mechanisms could be elaborated based on STM measurements, proving the general capability of this method for studying resistive switching phenomena in different classes of transition metal oxides.
authors.affiliation: Peter Grünberg Institut, Forschungszentrum Jülich , Wilhelm-Johnen-Straße, 52425 Jülich, Germany.
authors.forename: Marco
authors.initials: M
authors.lastname: Moors
authors.forename: Kiran Kumar
authors.initials: KK
authors.lastname: Adepalli
authors.forename: Qiyang
authors.initials: Q
authors.lastname: Lu
authors.affiliation: Peter Grünberg Institut, Forschungszentrum Jülich , Wilhelm-Johnen-Straße, 52425 Jülich, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Wedig
authors.affiliation: Peter Grünberg Institut, Forschungszentrum Jülich , Wilhelm-Johnen-Straße, 52425 Jülich, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Bäumer
authors.affiliation: Peter Grünberg Institut, Forschungszentrum Jülich , Wilhelm-Johnen-Straße, 52425 Jülich, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Skaja
authors.affiliation: Peter Grünberg Institut, Forschungszentrum Jülich , Wilhelm-Johnen-Straße, 52425 Jülich, Germany.
authors.forename: Benedikt
authors.initials: B
authors.lastname: Arndt
authors.forename: Harry Louis
authors.initials: HL
authors.lastname: Tuller
authors.affiliation: Peter Grünberg Institut, Forschungszentrum Jülich , Wilhelm-Johnen-Straße, 52425 Jülich, Germany.
authors.forename: Regina
authors.initials: R
authors.lastname: Dittmann
authors.affiliation: Peter Grünberg Institut, Forschungszentrum Jülich , Wilhelm-Johnen-Straße, 52425 Jülich, Germany.|Institut für Werkstoffe der Elektrotechnik 2, RWTH Aachen University , Sommerfeldstraße 24, 52074 Aachen, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Waser
authors.forename: Bilge
authors.initials: B
authors.lastname: Yildiz
authors.affiliation: Peter Grünberg Institut, Forschungszentrum Jülich , Wilhelm-Johnen-Straße, 52425 Jülich, Germany.|Institut für Werkstoffe der Elektrotechnik 2, RWTH Aachen University , Sommerfeldstraße 24, 52074 Aachen, Germany.
authors.forename: Ilia
authors.initials: I
authors.lastname: Valov
keywords: electric field effect; resistive switching; scanning tunneling microscopy; strontium ruthenate; tantalum oxide