Magnetic field dependence of critical currents in superconducting polycrystals

Journal Article · Mon Feb 10 00:00:00 EST 1992 · Modern Physics Letters B; (Singapore)

DOI:https://doi.org/10.1142/S021798499200020X· OSTI ID:7234586

Kugel, K I; Lisovskaya, T Y ^[1]; Mints, R G ^[2]

---

1. Inst. for High Temperatures, Russian Academy of Sciences, Moscow 127412 (SU)
2. School of Physics and Astronomy, Faculty of Exact Sciences, Tel Aviv Univ., Tel Aviv 69978 (IL)

The authors study the dependence of critical current j{sub c} on magnetic field H in superconducting polycrystals which are considered as system of superconducting crystallites (isotropic or anisotropic) with Josephson contacts between them. Isotropy or anisotropy of contacts depends on the orientation of their crystallographic axes relatively to edges of contact planes. In this paper it is shown that for a system of randomly oriented isotropic contacts, the dependence j{sub c}(H) in a relatively wide field range has the asymptotic form j{sub c} {approximately} (InH)/H{sup 2}. This differs drastically from j{sub c}(H) for single contacts. Anisotropy effects due to large differences in London penetration depth {lambda} values corresponding to external magnetic field directed along different axes are analyzed in detail. It is shown that for uniaxal crystals with {lambda}{sub 1} = {lambda}{sub 2} {lt} {lambda}{sub 3}, this anisotropy leads to the relation j{sub c} {approximately} {radical}{lambda}{sub 3}/{lambda}{sub 1} for chaotic orientation of crystallites. The form of j{sub c}(H) curves for two different orientations of the magnetic field relatively to the transport current through the sample is found.

• OSTI ID: 7234586
• Journal Information: Modern Physics Letters B; (Singapore), Vol. 6:3; ISSN 0217-9849
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
SUPERCONDUCTORS
CRITICAL CURRENT
PENETRATION DEPTH
ANISOTROPY
ASYMPTOTIC SOLUTIONS
ISOTROPY
JOSEPHSON JUNCTIONS
LONDON EQUATION
MAGNETIC FIELDS
POLYCRYSTALS
RANDOMNESS
CRYSTALS
CURRENTS
ELECTRIC CURRENTS
EQUATIONS
JUNCTIONS
SUPERCONDUCTING JUNCTIONS
665411* - Basic Superconductivity Studies- (1992-)