Nonlocal effects in magnetization of high-{kappa} superconductors

Journal Article · Sun Oct 01 04:00:00 EDT 2000 · Physical Review B

DOI:https://doi.org/10.1103/PhysRevB.62.9077· OSTI ID:40205607

Kogan, V G; Bud'ko, S L; Fisher, I R; Canfield, P C

The reversible magnetization M(T,H) in high quality single crystals of Lu(Ni{sub 1-x}Co{sub x}){sub 2}B{sub 2}C with x=0-0.09 is measured in a broad T,H domain and interpreted within London theory corrected for nonlocality of the current -- vector-potential relation. Profound deviations in the data from the standard London result, M{proportional_to}ln(H{sub c2}/H) in intermediate fields H{sub c1}<<H<<H{sub c2}, are seen in clean samples at low T 's.Unlike strongly anisotropic high-T{sub c} compounds, for nearly isotropic borocarbides this behavior cannot be attributed to fluctuations of weakly interacting pancake vortices. We show that the nonlocal London model describes qualitatively and consistently the whole set of M(T,H) data and, in particular, its temperature and the mean-free path dependence. The scaling field H{sub 0}, which arises in M=M(H/H{sub 0}) due to nonlocality, is found to be nearly proportional to the the field H{sub 2} at which the vortex lattice undergoes the symmetry change (the ''square-to-hex'' transition).

• Sponsoring Organization: (US)
• OSTI ID: 40205607
• Journal Information: Physical Review B, Journal Name: Physical Review B Journal Issue: 13 Vol. 62; ISSN 0163-1829
• Publisher: The American Physical Society
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
FLUCTUATIONS
MAGNETIZATION
MONOCRYSTALS
SUPERCONDUCTORS
SYMMETRY
VORTICES