In situ examination of oxygen non-stoichiometry in La0.80Sr0.20CoO3 thin films at intermediate and low temperatures by X-ray diffraction

Journal Article · Wed Jan 01 00:00:00 EST 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4873542· OSTI ID:1133579

Biegalski, Michael D ^[1]; Crumlin, Ethan ^[2]; Belianinov, Alex ^[1]; Mutoro, Eva ^[2]; Shao-Horn, Yang ^[2]; Kalinin, Sergei ^[3]

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1. ORNL
2. Massachusetts Institute of Technology (MIT)
3. Oak Ridge National Laboratory (ORNL)

Structural evolution of epitaxial La0.80Sr0.20CoO3 thin films under chemical and voltage stimuli were examined in situ using X-ray diffraction. The changes in lattice parameter (chemical expansivity) were used to quantify oxygen reduction reaction processes and vacancy concentration changes in LSCO. At 550 C the observed lattice parameter reduction at an applied bias of 0.6 V was equivalent to that from the reducing condition of a two percent carbon monoxide atmosphere with an oxygen non-stoichiometry of 0.24. At lower temperatures (200 C) the application of bias reduced the sample much more effectively than a carbon monoxide atmosphere and induced an oxygen non-stoichiometry of 0.47. Despite these large changes in oxygen concentration, the epitaxial thin film was completely re-oxidized and no signs of crystallinity loss or film amorphization were observed. This work demonstrates that the effects of oxygen evolution and reduction can be examined with applied bias at low temperatures, extending the ability to probe these processes with in-situ analytical techniques.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1133579
• Journal Information: Applied Physics Letters, Vol. 104, Issue 16; ISSN 0003--6951
• Country of Publication: United States
• Language: English

Related Subjects

Oxygen evoltion
Oxygen Reduction
Thin film