Probing the oxygen vacancy distribution in resistive switching Fe-SrTiO3 metal-insulator-metal-structures by micro-x ray absorption near-edge structure

Abstract

Resistive switching metal-insulator-metal structures were fabricated from epitaxial Fe-doped SrTiO3 thin films to study the distribution of oxygen vacancies in a switched memristor cell using a micro-focused x-ray beam. In addition to the main filament, we found that the concentration of oxygen vacancies increases homogeneously over the whole electrode area during the electroforming procedure. The x-ray absorption near-edge structure (XANES) observed at the location of the filament exhibits distinct differences to the surrounding area, which are interpreted with full-multiple-scattering XANES calculations to derive from oxygen vacancy clustering in the first coordination shell around Fe.

Donor‐Induced Performance Tuning of Amorphous SrTiO3 Memristive Nanodevices: Multistate Resistive Switching and Mechanical Tunability

“…[1][2][3][4]13,15,30,32,38 ] In order to investigate the chemical states in a -STO thin fi lms and the impact of the compositional changes on the memristive behavior of a -STO MIM devices, a detailed analysis of the X-ray photoelectron spectroscopy (XPS)-binding energy spectra of the principal elements was carried out throughout the thickness of virgin and active devices (see Section S3, Supporting Information). [1][2][3][4]13,15,30,32,38 ] In order to investigate the chemical states in a -STO thin fi lms and the impact of the compositional changes on the memristive behavior of a -STO MIM devices, a detailed analysis of the X-ray photoelectron spectroscopy (XPS)-binding energy spectra of the principal elements was carried out throughout the thickness of virgin and active devices (see Section S3, Supporting Information).…”

Determination of the electrostatic potential distribution in Pt/Fe:SrTiO3/Nb:SrTiO3 thin-film structures by electron holography

“…Since there is experimental evidence that the nominally acceptor-doped Fe:SrTiO 3 layer contains a large amount of donor-type oxygen vacancies generated during sample fabrication26, different distributions of acceptor-type and donor-type dopants of concentrations N A and N VO were considered in the I-layer.…”

Investigation of the Eightwise Switching Mechanism and Its Suppression in SrTiO3 Modulated by Humidity and Interchanged Top and Bottom Platinum and LaNiO3 Electrode Contacts

“…[22] The switching polarity has been consistently different with both dopants, Nb exhibiting eightwise polarity [22,23] and Fe counter-eightwise or both competing polarities. [25,29,32,33] Competing switching polarities dependent on the electrical field are possible in a single switching bit [25,29] and a debate in the literature has been ongoing about the switching mechanism in devices with the eightwise polarity. [19,34] Recently, Cooper et al proposed oxygen evolution and reincorporation into the high work function platinum electrode as the mechanism in undoped SrTiO 3 .…”