Evidence of surface barriers in single-crystal Tl[sub 2]Ba[sub 2]CuO[sub 6] superconductors
- Physics Department, University of Miami, Coral Gables, Florida 33124 (United States)
- Department of Physics, University of Colorado, Boulder, Colorado 80309 (United States)
We report direct evidence of surface barriers in single crystals of Tl[sub 2]Ba[sub 2]CuO[sub 6] superconductors. Magnetization is measured as a function of temperature with magnetic field applied parallel to the [ital c] axis. For small field, a characteristic linear increase in [ital M] is observed at an onset temperature [ital T][sub 1]. For higher magnetic field, a new feature at low [ital T] is observed in the [ital M]([ital T]) data. The flux penetration temperature is retarded to a higher temperature. The penetration field [ital H][sub [ital p]] at temperature below 50 K determined by the first linear rise in [ital M]([ital T]) can be fitted with the relation [ital H][sub [ital p]]([ital T])=[ital H][sub [ital c]]exp([minus][ital T]/[ital T][sub 0]), consistent with a model where two-dimensional pancakes penetrate the Bean-Livingston barrier by thermal activation. The low critical field [ital H][sub [ital c]1][sup [perpendicular]] determined from the bulk penetration of vortices is also presented.
- OSTI ID:
- 5579035
- Journal Information:
- Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 47:9; ISSN 0163-1829; ISSN PRBMDO
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360207* -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
COPPER COMPOUNDS
CRITICAL FIELD
CRYSTALS
CUPRATES
HIGH-TC SUPERCONDUCTORS
MAGNETIC FIELDS
MAGNETIZATION
MONOCRYSTALS
OXYGEN COMPOUNDS
PENETRATION DEPTH
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE
THALLIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TUNNEL EFFECT