High-transport current density up to 30 T in bulk YBa sub 2 Cu sub 3 O sub 7 and the critical angle effect

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

DOI:https://doi.org/10.1063/1.105595· OSTI ID:5554055

Ekin, J W ^[1]; Salama, K; Selvamanickam, V ^[2]

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1. Electromagnetic Technology Division, National Institute of Standards and Technology, Boulder, Colorado 80303 (US)
2. Texas Center for Superconductivity at University of Houston, Houston, Texas 77004 (USA)

Measurements of the dc {ital transport} critical current of oriented-grained YBa{sub 2}Cu{sub 3}O{sub 7} have been made using high quality Ag contacts and a high-current sample mount. The critical- current density {ital J}{sub {ital c}} at 77 K for mutually perpendicular current and magnetic field B in the {ital a},{ital b} plane is 8 kA/cm{sup 2} at 8 T, decreasing gradually to 3.7 kA/cm{sup 2} at 20 T, and remaining over 1 kA/cm{sup 2} out to 30 T. High magnetic field measurements of {ital J}{sub {ital c}} as a function of the angle {theta} of B with respect to the {ital c} axis are also reported. In contrast to earlier results at lower fields ({lt}3 T) the measurements reported here in high fields reveal a {ital J}{sub {ital c}} vs {theta} curve with a {ital head}-{ital and}-{ital shoulders} shape, consisting of a sharp peak ( head'') {lt}5{degree} wide for B parallel to the CuO{sub 2} planes, and a wide (30{degree} at 9 T, for example) shoulder region on either side of {ital B}{perpendicular}{ital c}, where the transport {ital J}{sub {ital c}} remains high and constant. Beyond the shoulder region, however, the transport {ital J}{sub {ital c}} decreases sharply, giving rise to the concept of a {ital critical} {ital field} {ital angle} for application design, defined by the minima in {ital d}{sup 2}{ital J}{sub {ital c}}/{ital d}{theta}{sup 2} at the edge of the shoulders.

• OSTI ID: 5554055
• Journal Information: Applied Physics Letters; (USA), Journal Name: Applied Physics Letters; (USA) Vol. 59:3; ISSN APPLA; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CRITICAL CURRENT
CURRENTS
ELECTRIC CONDUCTIVITY
ELECTRIC CURRENTS
ELECTRICAL PROPERTIES
HIGH-TC SUPERCONDUCTORS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SUPERCONDUCTIVITY
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES