Experimental determination of the upper critical field of epitaxially grown thin films of YBa sub 2 Cu sub 3 O sub 7 minus. delta. down to He temperature

Journal Article · Thu Aug 15 04:00:00 EDT 1991 · Journal of Applied Physics; (United States)

DOI:https://doi.org/10.1063/1.349435· OSTI ID:5329194

Woerdenweber, R; Abd-El-Hamed, M O; Schneider, J ^[1]; Laborde, O ^[2]

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1. Institute of Thin Film and Ion Technology, Forschungszentrum Juelich, P.O. Box 1913, D-5170 Juelich (Federal Republic of Germany)
2. Service National des Champs Intenses, CNRS, BP 166X, 38042 Grenoble (France)

The upper critical field of YBa{sub 2}(Cu{sub 1{minus}{ital x}}Fe{sub {ital x}}){sub 3}O{sub 7{minus}{delta}} with {ital x}=0 and 0.05 is determined over the whole temperature range from 4.2 K to {ital T}{sub {ital c}}. The data behave according to the theory of Werthamer, Helfand, and Hohenberg (N. R. Werthamer, E. Helfand, and P. C. Hohenberg, Phys. Rev. {bold 147}, 295 (1966)). However, at low temperatures the upper critical field is larger than expected from the original expressions of Werthamer and co-workers. Generalized equations, which take into account the anisotropy of the Fermi surface, yield values for the upper critical field, which are in excellent agreement with the experimental data.

• OSTI ID: 5329194
• Journal Information: Journal of Applied Physics; (United States), Journal Name: Journal of Applied Physics; (United States) Vol. 70:4; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
ANISOTROPY
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CRITICAL FIELD
ENERGY LEVELS
EPITAXY
FERMI LEVEL
FILMS
HIGH-TC SUPERCONDUCTORS
IRON COMPOUNDS
IRON OXIDES
LOW TEMPERATURE
MAGNETIC FIELDS
MATHEMATICAL MODELS
OXIDES
OXYGEN COMPOUNDS
SUPERCONDUCTING FILMS
SUPERCONDUCTORS
THIN FILMS
TRANSITION ELEMENT COMPOUNDS
ULTRALOW TEMPERATURE
VERY LOW TEMPERATURE
YTTRIUM COMPOUNDS
YTTRIUM OXIDES