Periodic pin array at the fluxon lattice scale in a high-field superconducting wire

Journal Article · Mon Mar 07 04:00:00 EST 1994 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.111940· OSTI ID:142576

Cooley, L D; Lee, P J; Larbalestier, D C ^[1]; O`Larey, P M ^[2]

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1. Applied Superconductivity Center, University of Wisconsin-Madison, 1500 Johnson Drive, Madison, Wisconsin 53706 (United States)
2. Teledyne Wah Chang Albany, Albany, Oregon 97321 (United States)

A periodic pin array has been made at dimensions approaching the diameter and spacing of the fluxon cores in an ``island``-type of artificial pinning center superconducting composite wire. Gun-barrel drilling was used to precisely incorporate a hexagonal array of Nb 1.3 wt. % Ti pinning centers into an ingot of Nb 46.5 wt. % Ti, before extrusion and wire drawing. Transmission electron microscopy images showed little evidence of pin geometry alteration down to 100 nm pin diameter. At {similar_to}30 nm effective pin diameter, the aspect ratio of the pins was 3--5, and the pin array retained its hexagonal geometry. Bulk pinning force curves had temperature-independent structure down to 15 nm effective pin diameter, suggestive of matching between fluxons and pins. Because of the uniform pin geometry, the maximum bulk pinning force exceeded that of the best conventional composites, even though the upper critical field and the volume fraction of pins were significantly lower.

• OSTI ID: 142576
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 10 Vol. 64; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
BINARY ALLOY SYSTEMS
CRITICAL CURRENT
DEFECTS
MICROSTRUCTURE
NIOBIUM BASE ALLOYS
SUPERCONDUCTING COMPOSITES
SUPERCONDUCTING MAGNETS
SUPERCONDUCTING WIRES
SYNTHESIS
TITANIUM ALLOYS
VORTICES