Publication Date
2019
Journal or Book Title
Science Advances
Abstract
Oxygen vacancies () play a critical role as defects in complex oxides in establishing functionality in systems including memristors, all-oxide electronics, and electrochemical cells that comprise metal-insulator-metal or complex oxide heterostructure configurations. Improving oxide-oxide interfaces necessitates a direct, spatial understanding of vacancy distributions that define electrochemically active regions. We show vacancies deplete over micrometer-level distances in Nb-doped SrTiO3 (Nb:SrTiO3) substrates due to deposition and post-annealing processes. We convert the surface potential across a strontium titanate/yttria-stabilized zirconia (STO/YSZ) heterostructured film to spatial (<100 >nm) vacancy profiles within STO using (T = 500°C) in situ scanning probes and semiconductor analysis. Oxygen scavenging occurring during pulsed laser deposition reduces Nb:STO substantially, which partially reoxidizes in an oxygen-rich environment upon cooling. These results (i) introduce the means to spatially resolve quantitative vacancy distributions across oxide films and (ii) indicate the mechanisms by which oxide thin films enhance and then deplete vacancies within the underlying substrate.
ORCID
https://orcid.org/0000-0002-5369-9279
DOI
https://doi.org/10.1126/sciadv.aau8467
Volume
5
Issue
2
License
UMass Amherst Open Access Policy
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License
Funder
UMass SOAR Fund
Recommended Citation
Zhu, Jiaxin; Lee, Jung-Woo; Lee, Hyungwoo; Xie, Lin; Pan, Xiaoqing; De Souza, Roger A.; Eom, Chang-Beom; and Nonnenmann, Stephen S., "Probing vacancy behavior across complex oxide heterointerfaces" (2019). Science Advances. 622.
https://doi.org/10.1126/sciadv.aau8467