Computation of superconductor critical current densities and magnetization curves

Journal Article · Mon Apr 15 04:00:00 EDT 1991 · Journal of Applied Physics; (USA)

DOI:https://doi.org/10.1063/1.348222· OSTI ID:5570499

Hodgdon, M L ^[1]

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1. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (US)

Using a constitutive law for superconductor hysteresis and the ideas of the critical state model, a system of equations is developed for the critical current density {ital J}{sub {ital c}}, the equilibrium magnetization {ital M}{sub {ital e}}, the upper and lower portions {ital M}{sub {ital U}} and {ital M}{sub {ital L}} of the major hysteresis loop, and their derivatives with respect to the applied field. The constitutive law consists of the differential equation {ital dB}/{ital dH}={alpha}({ital H}){ital s}({ital {dot H}})({ital f}({ital H}){minus}{ital B})+{ital g}({ital H}) for {ital {dot H}}{ne}0, and a rule governing the abrupt changes observed at the turning points of {ital H}. For the case presented here in which {ital f}, {ital g}, and {alpha} have analytic forms, the constitutive law yields an easily differentiable expression for the major loop. Hysteresis curves computed from this constitutive law are shown to be in good agreement with experiments. Exponential approximations are given for the critical current densities computed by this method for a polycrystalline sample of YBa{sub 2}Cu{sub 3}O{sub {ital x}} between 5 and 40 K.

• OSTI ID: 5570499
• Journal Information: Journal of Applied Physics; (USA), Journal Name: Journal of Applied Physics; (USA) Vol. 69:8; 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
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CRITICAL CURRENT
CRYSTALS
CURRENT DENSITY
CURRENTS
ELECTRIC CONDUCTIVITY
ELECTRIC CURRENTS
ELECTRICAL PROPERTIES
HYSTERESIS
MAGNETIZATION
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POLYCRYSTALS
SUPERCONDUCTIVITY
TRANSITION ELEMENT COMPOUNDS
ULTRALOW TEMPERATURE
VERY LOW TEMPERATURE
YTTRIUM COMPOUNDS
YTTRIUM OXIDES