TY  - JOUR
AU  - Lenser, Christian
AU  - Koehl, Annemarie
AU  - Slipukhina, Ivetta
AU  - Du, Hongchu
AU  - Patt, Marten
AU  - Feyer, Vitaliy
AU  - Schneider, Claus M.
AU  - Lezaic, Marjana
AU  - Waser, R.
AU  - Dittmann, Regina
TI  - Formation and Movement of Cationic Defects During Forming and Resistive Switching in SrTiO $_{3}$ Thin Film Devices
JO  - Advanced functional materials
VL  - 25
IS  - 40
SN  - 1616-301X
CY  - Weinheim
PB  - Wiley-VCH
M1  - FZJ-2015-06295
SP  - 6360 - 6368
PY  - 2015
AB  - The resistance switching phenomenon in many transition metal oxides is described by ion motion leading to the formation of oxygen-deficient, highly electron-doped filaments. In this paper, the interface and subinterface region of electroformed and switched metal–insulator–metal structures fabricated from a thin Fe-doped SrTiO3 (STO) film on n-conducting Nb-doped SrTiO3 crystals are investigated by photoemission electron microscopy, transmission electron microscopy, and hard X-ray photoelectron spectroscopy in order to gain a deeper understanding of cation movement in this specific system. During electroforming, the segregation of Sr to the top interface and the generation of defect-rich cones in the film are observed, apparently growing from the anode toward the cathode during electroforming. An unusual binding energy component of the Sr 3d emission line is observed which can be assigned to inline image defect complexes by performing ab initio calculations. Since this Sr component can be reversibly affected by an external electrical bias, the movement of both oxygen and Sr point defects and the formation of defect complexes inline image during resistive switching are suggested. These findings are discussed with regard to the point defect structure of the film and the local oxidation of the donor-doped substrate. In particular, the apparent dichotomy between the observation of acceptor-type defects and increased electronic conductivity in STO is addressed.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000363685900006
DO  - DOI:10.1002/adfm.201500851
UR  - https://juser.fz-juelich.de/record/256335
ER  -