Critical fields and vortex structure of YBa sub 2 Cu sub 3 O sub 7 minus. delta. derived from reversible magnetization

Journal Article · Wed Jul 01 04:00:00 EDT 1992 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.46.398· OSTI ID:5000213

Gohng, J; Finnemore, D K ^[1]

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1. Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States)

The magnetic-field and temperature dependence of the Ginzburg-Landau order parameter {l angle}{ital f}{r angle} is derived from magnetization studies for grain-aligned YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} in the region of thermodynamic reversibility, based on the Hao-Clem model. The value of {l angle}{ital f}{r angle} at 5 T and 89 K is still 52.3% of the zero-field value. Fitting the magnetization data to the Hao-Clem theory reveals that {kappa}{sub {ital c}} is a slowly decreasing function of temperature near {ital T}{sub {ital c}}. {ital H}{sub {ital c}}({ital T}) and {ital H}{sub {ital c}2}({ital T}) were determined with high precision along with the {kappa}{sub {ital c}}({ital T}) values. The detailed shape of the order parameter is derived from {kappa}{sub {ital c}}({ital T}) and {ital H}{sub {ital c}}({ital T}) data. Characteristic variables derived from the data are {ital H}{sub {ital c}}(0)=1.18{times}10{sup 4} Oe, {lambda}{sub {ital a}{ital b}}(0)=1.31{times}10{sup 3} A, and {xi}{sub {ital a}{ital b}}(0)=18 A. The BCS fitting of {ital H}{sub {ital c}} reveals that the value of {minus}{ital dH}{sub {ital c}2}/{ital dT} decreases from 2.25 T/K at {ital T}=82 to 1.9 T/K at {ital T}{sub {ital c}} of 92.4 K.

• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 5000213
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 46:1; ISSN 0163-1829; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360207* -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
BCS THEORY
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CRITICAL FIELD
HIGH-TC SUPERCONDUCTORS
MAGNETIC FIELDS
MAGNETIC FLUX
MAGNETIZATION
ORDER PARAMETERS
OXIDES
OXYGEN COMPOUNDS
SUPERCONDUCTORS
TEMPERATURE EFFECTS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES