Desorption of oxygen from YBa{sub 2}Cu{sub 3}O{sub 6+{ital x}} films studied by Raman spectroscopy

Journal Article · Thu Aug 01 04:00:00 EDT 1996 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.54.4300· OSTI ID:286700

Bock, A; Kuersten, R; Bruehl, M; Dieckmann, N; Merkt, U ^[1]

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1. Institut fuer Angewandte Physik und Zentrum fuer Mikrostrukturforschung, Universitaet Hamburg, Jungiusstrae 11, D-20355 Hamburg (Germany)

Phonons of laser-deposited YBa{sub 2}Cu{sub 3}O{sub 6+{ital x}} films on MgO(100) substrates are investigated in a Raman setup as a function of laser power density. Investigations of YBa{sub 2}Cu{sub 3}O{sub 7} films allow us to study oxygen out-diffusion, where the onset of out-diffusion is indicated by the appearance of disorder-induced modes in the Raman spectra. At a pressure of 5{times}10{sup {minus}6} mbar the temperature threshold of the out-diffusion is (490{plus_minus}15) K. With increasing oxygen pressure the observed temperature thresholds rise only moderately in contrast to the behavior expected from the {ital p}{sub ox}-{ital T} phase diagram of YBa{sub 2}Cu{sub 3}O{sub 6+{ital x}}. Even at 1 bar oxygen partial pressure out-diffusion is observed and tetragonal sites with {ital x}=0 develop. These observations can be explained by photon-stimulated desorption of oxygen. Investigations of YBa{sub 2}Cu{sub 3}O{sub 6} films allow us to study oxygen in-diffusion. In 1 bar oxygen we observe competing oxygen fluxes due to thermally activated diffusion and photon-stimulated desorption. From these measurements we determine an upper bound of the thermal activation energy of the oxygen in-diffusion into YBa{sub 2}Cu{sub 3}O{sub 6} films of (0.19{plus_minus}0.01) eV. {copyright} {ital 1996 The American Physical Society.}

• OSTI ID: 286700
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 6 Vol. 54; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACTIVATION ENERGY
ATOM TRANSPORT
BARIUM OXIDES
COPPER OXIDES
DESORPTION
DIFFUSION
HIGH-TC SUPERCONDUCTORS
OXYGEN
RAMAN SPECTRA
SORPTIVE PROPERTIES
SUPERCONDUCTING FILMS
TEMPERATURE DEPENDENCE
YTTRIUM OXIDES