Surface pinning as a determinant of the bulk flux-line lattice structure in copper oxide superconductors

Journal Article · Fri Jul 08 04:00:00 EDT 1994 · Science (Washington, D.C.); (United States)

DOI:https://doi.org/10.1126/science.265.5169.215· OSTI ID:6765641

Yoon, Seokwon; Dai, Hongjie; Liu, Jie; Lieber, C M ^[1]

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1. Harvard Univ., Cambridge, MA (United States)

Direct knowledge of crystal defects and their perturbation of magnetic flux lines is essential to understanding pinning and to devising approaches that enhance critical currents in superconductors with high critical temperatures (T[sub c]). Atomic force microscopy was used to simultaneously characterize crystal defects and the magnetic flux-line lattice in single crystals of Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub 8]. Images show that surface defects, which are present on all real samples, pin the flux-line lattice. Above a critical height, the pinning interaction is sufficiently strong to form grain boundaries in the bulk flux-line lattice. These results elucidate the structure of the defects that pin flux lines and demonstrate that surface pinning, through the formation of grain boundaries, can determine the bulk flux-line lattices structure in high-T[sub c] materials. The implications of these results to the bulk flux-line lattice structure observed in previous experiments and to enhancing critical currents are discussed.

• OSTI ID: 6765641
• Journal Information: Science (Washington, D.C.); (United States), Journal Name: Science (Washington, D.C.); (United States) Vol. 265:5169; ISSN SCIEAS; ISSN 0036-8075
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
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ALKALINE EARTH METAL COMPOUNDS
BISMUTH COMPOUNDS
CALCIUM COMPOUNDS
COPPER COMPOUNDS
CRITICAL CURRENT
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
CUPRATES
CURRENTS
ELECTRIC CURRENTS
HIGH-TC SUPERCONDUCTORS
OXYGEN COMPOUNDS
STRONTIUM COMPOUNDS
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TRANSITION ELEMENT COMPOUNDS