Vacancy defects in thin-film La{sub 0.5}Sr{sub 0.5}CoO{sub 3{minus}{delta}} observed by positron annihilation

Journal Article · Wed Jul 01 00:00:00 EDT 1998 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.121916· OSTI ID:639050

Keeble, D J ^[1]; Krishnan, A; Friessnegg, T; Nielsen, B ^[2]; Madhukar, S; Aggarwal, S; Ramesh, R ^[3]; Poindexter, E H ^[4]

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1. Carnegie Laboratory of Physics, University of Dundee, Dundee DD1 4HN (United Kingdom)
2. Division of Materials Science, Brookhaven National Laboratory, Upton, New York 11793 (United States)
3. Department of Materials Science and Nuclear Engineering, University of Maryland, College Park, Maryland 20742 (United States)
4. Army Research Laboratory, Adelphi, Maryland 20742 (United States)

Vacancy-related defects in laser ablated thin films of the conducting metal{endash}oxide La{sub 0.5}Sr{sub 0.5}CoO{sub 3{minus}{delta}} were detected using a variable-energy positron beam. The nonstoichiometry, {delta}, was altered by varying the oxygen partial pressure within the deposition chamber present during cooling. Conductivity measurements confirmed the change in oxygen content. Increased positron trapping at vacancy defects was observed with increasing nonstoichiometry. It is proposed that vacancy clusters were present in the film cooled in 10{sup {minus}5}thinspTorr oxygen. {copyright} {ital 1998 American Institute of Physics.}

• OSTI ID: 639050
• Journal Information: Applied Physics Letters, Vol. 73, Issue 4; Other Information: PBD: Jul 1998
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
LANTHANUM COMPOUNDS
STRONTIUM COMPOUNDS
ELECTRIC CONDUCTIVITY
PEROVSKITES
LANTHANUM OXIDES
STRONTIUM OXIDES
COBALT OXIDES
THIN FILMS
CRYSTAL DEFECTS
VACANCIES
POSITRON BEAMS
STOICHIOMETRY