TY  - JOUR
AU  - Rodenbücher, Christian
AU  - Bittkau, Karsten
AU  - Bihlmayer, Gustav
AU  - Wrana, Dominik
AU  - Gensch, Thomas
AU  - Korte, Carsten
AU  - Krok, Franciszek
AU  - Szot, Kristof
TI  - Mapping the conducting channels formed along extended defects in SrTiO3 by means of scanning near-field optical microscopy
JO  - Scientific reports
VL  - 10
IS  - 1
SN  - 2045-2322
CY  - [London]
PB  - Macmillan Publishers Limited, part of Springer Nature
M1  - FZJ-2020-04110
SP  - 17763
PY  - 2020
AB  - Mixed ionic-electronic-conducting perovskites such as SrTiO3 are promising materials to be employed in efficient energy conversion or information processing. These materials exhibit a self-doping effect related to the formation of oxygen vacancies and electronic charge carriers upon reduction. It has been found that dislocations play a prominent role in this self-doping process, serving as easy reduction sites, which result in the formation of conducting filaments along the dislocations. While this effect has been investigated in detail with theoretical calculations and direct observations using local-conductivity atomic force microscopy, the present work highlights the optical properties of dislocations in SrTiO3 single crystals. Using the change in optical absorption upon reduction as an indicator, two well-defined arrangements of dislocations, namely a bicrystal boundary and a slip band induced by mechanical deformation, are investigated by means of scanning near-field optical microscopy. In both cases, the regions with enhanced dislocation density can be clearly identified as regions with higher optical absorption. Assisted by ab initio calculations, confirming that the agglomeration of oxygen vacancies significantly change the local dielectric constants of the material, the results provide direct evidence that reduced dislocations can be classified as alien matter embedded in the SrTiO3 matrix.
LB  - PUB:(DE-HGF)16
C6  - pmid:33082447
UR  - <Go to ISI:>//WOS:000585236900022
DO  - DOI:10.1038/s41598-020-74645-1
UR  - https://juser.fz-juelich.de/record/885819
ER  -