Comparison of experimental magnetization and specific-heat data with Landau-Ginzburg theory results for high-temperature superconductors near [ital H][sub [ital c]2]

Journal Article · Sun Aug 01 00:00:00 EDT 1993 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.48.3464· OSTI ID:5578950

Wilkin, N K; Moore, M A ^[1]

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1. Department of Theoretical Physics, University of Manchester, Manchester, M13 9PL (United Kingdom)

We have recently studied the magnetization and specific heat for two- and three-dimensional superconductors, starting from Landau-Ginzburg theory. In this paper we compare the results of this study with available experimental data. All our results have been calculated for a strong magnetic field along the [ital c] axis in the region near the [ital H][sub [ital c]2] line where the lowest-Landau-level approximation is valid. We show that the theoretical two-dimensional magnetization compares very well with that measured for the high-[ital T][sub [ital c]] superconductor Bi 2:2:2:3, which is a quasi-two-dimensional system. Our comparison leads to an estimate of [kappa], the Ginzburg-Landau parameter as [kappa][congruent]140. In three dimensions a reasonable fit to the specific heat for a conventional superconductor (niobium) is obtained, but the anisotropic Landau-Ginzburg theory cannot be made to fit YBa[sub 2]Cu[sub 3]O[sub 7[minus][delta]] over any sizable temperature range. It is only when the Lawrence-Doniach model is considered (which takes into account the layered structure of the system) that a fit becomes possible over any temperature range. At high temperatures the form of this function is the same as the two-dimensional Landau-Ginzburg theory and the fact that this fits the experimental data indicates that the layers are acting independently.

• OSTI ID: 5578950
• Journal Information: Physical Review, B: Condensed Matter; (United States), Vol. 48:5; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
HIGH-TC SUPERCONDUCTORS
GINZBURG-LANDAU THEORY
MAGNETIZATION
SPECIFIC HEAT
CRITICAL FIELD
EXPERIMENTAL DATA
FLUCTUATIONS
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES
TWO-DIMENSIONAL CALCULATIONS
TYPE-II SUPERCONDUCTORS
DATA
INFORMATION
MAGNETIC FIELDS
NUMERICAL DATA
PHYSICAL PROPERTIES
SUPERCONDUCTORS
VARIATIONS
360207* - Ceramics
Cermets
& Refractories- Superconducting Properties- (1992-)