TY  - JOUR
AU  - Rheinheimer, Wolfgang
AU  - Phuah, Xin Li
AU  - Wang, Han
AU  - Lemke, Fabian
AU  - Hoffmann, Michael J.
AU  - Wang, Haiyan
TI  - The role of point defects and defect gradients in flash sintering of perovskite oxides
JO  - Acta materialia
VL  - 165
SN  - 1359-6454
CY  - Amsterdam [u.a.]
PB  - Elsevier Science
M1  - FZJ-2020-04452
SP  - 398 - 408
PY  - 2019
AB  - The present study investigates the impact of point defects and their redistribution on the flash sintering process. Strontium titanate was chosen as a model system for the group of perovskite ceramics. The characteristics of flash sintering of strontium titanate were analyzed with different acceptor dopant concentrations. The onset of flash sintering was found to be dependent on the acceptor dopant concentration, as expected by the increasing conductivity. A gradient in the microstructure was found after flash sintering with larger grain sizes at the negative electrode. TEM-EDS measurements indicated Ti enrichment at the positive electrode for undoped strontium titanate and strong acceptor segregation for doped strontium titanate. In contrast, grain boundaries at the negative electrode were found to be stoichiometric for the undoped case and the acceptor segregation was less obvious for the doped case.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000457665100036
DO  - DOI:10.1016/j.actamat.2018.12.007
UR  - https://juser.fz-juelich.de/record/887826
ER  -