Berlin 2012 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
DF: Fachverband Dielektrische Festkörper
DF 18: Resistive switching I (jointly with DS, KR, HL)
DF 18.2: Talk
Friday, March 30, 2012, 09:45–10:00, H 0111
Elucidation of the resistive switching in SrTiO3 MIM-structures by µXANES — •Christian Lenser1,2, Alexei Kuzmin3, Alexandr Kalinko3, Juris Purans3, Rainer Waser1,2,4, and Regina Dittmann1,2 — 1Peter Grünberg Institut 7, Forschungszentrum Jülich, 52425 Jülich, Germany — 2Jülich-Aachen Research Alliance, Section Fundamentals of Future Information Technology (JARA-FIT), Germany — 3Institute of Solid State Physics, University of Latvia, Kengaraga Street 8, LV- 1063 Riga, Latvia — 4Institut für Werkstoffe der Elektrotechnik, RWTH Aachen, 52056 Aachen, Germany
The resistive switching effect in Fe-doped SrTiO3 thin films is investigated on 100 µm2 metal-insulator-metal (MIM) structures by chemical mapping in the µm regime. X-ray absorption fine structure (XAFS) - measured at beamline ID03, ESRF - with a x-ray beam focused to several µm provides information about the absorption fine structure modulations at the Fe K-edge. The increase of pre-edge intensity characteristic of oxygen vacancies in the first coordination shell of the transition metal dopant shows the films to be highly oxygen deficient after growth. In addition to an increase of the Fe-VO•• concentration over the whole electrode area after electroforming, µm-sized mapping of a MIM-structure reveals the location of the conducting filament by a strong local change in the absorption edge, which is localized to a size of the order of 1 µm. The change of the absorption characteristics is interpreted with full multiple-scattering XANES simulations, suggesting oxygen vacancy clustering around Fe as the likely explanation.