Determination of the upper critical field of the electron-doped superconductor Sm[sub 1. 85]Ce[sub 0. 15]CuO[sub 4[minus][ital y]] from resistive fluctuations

Journal Article · Tue Dec 01 04:00:00 EST 1992 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.46.14290· OSTI ID:6957870

Han, S H; Almasan, C C; de Andrade, M C; Dalichaouch, Y; Maple, M B ^[1]

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1. Department of Physics and Institute for Pure and Applied Physical Sciences, University of California, San Diego, La Jolla, California 92093 (United States)

The upper critical field [ital H][sub [ital c]2]([ital T]) for the magnetic field applied parallel to the [ital c] axis of a Sm[sub 1.85]Ce[sub 0.15]CuO[sub 4[minus][ital y]] single crystal has been determined from an analysis of magnetoresistance data in terms of the Ginzburg-Landau fluctuation theory for layered superconductors. The fluctuations are predominantly two dimensions (2D) away from [ital T][sub [ital c]]([ital H]) with a crossover to 3D as [ital T][sub [ital c]]([ital H]) is approached. The [ital H][sub [ital c]2]([ital T]) curve shows negative curvature and is in excellent agreement with the Werthamer, Helfand, Hohenberg, and Maki theory for conventional superconductors without paramagnetic limiting effects. The values of the initial slope ([ital dH][sub [ital c]2]/[ital dT])[sub [ital T][ital c]]=[minus]7.38 kOe/K, coherence length [xi](0)=48.4 A, and orbital critical field [ital H][sub [ital c]2](0)=97.6 kOe, derived from this analysis, are in good agreement with the values we previously obtained from fits of the Hao-Clem variational model to reversible magnetization data below [ital T][sub [ital c]].

• DOE Contract Number: FG03-86ER45230
• OSTI ID: 6957870
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 46:21; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360207* -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
CERIUM COMPOUNDS
CERIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CRITICAL FIELD
CRYSTALS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
HIGH-TC SUPERCONDUCTORS
MAGNETIC FIELDS
MAGNETORESISTANCE
MONOCRYSTALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
SAMARIUM COMPOUNDS
SAMARIUM OXIDES
SUPERCONDUCTORS
TEMPERATURE EFFECTS
TRANSITION ELEMENT COMPOUNDS