Flux pinning by Y[sub 2]BaCuO[sub 5] precipitates and field- and temperature-driven pinning centers in melt-powder-melt-growth processed YBa[sub 2]Cu[sub 3]O[sub 7]

Journal Article · Mon Nov 01 00:00:00 EST 1993 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.48.13922· OSTI ID:6082382

Kung, P J; Maley, M P; McHenry, M E; Willis, J O ^[1]; Murakami, M; Tanaka, S ^[2]

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1. Superconductivity Technology Center, MS K763, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2. Superconductivity Research Laboratory, International Superconductivity Technology Center, 1-10-13 Shinonome, Koto-Ku, Tokyo 135 (Japan)

Magnetic hysteresis, flux pinning, and flux creep in melt-powder-melt-growth processed YBa[sub 2]Cu[sub 3]O[sub 7] (Y 1:2:3) containing nominal 0, 25, and 40 mol % concentration of Y[sub 2]BaCuO[sub 5] (Y 2:1:1) inclusions were investigated. The strong pinning due to 2:1:1-phase precipitates in these samples allows for characterization of the hysteretic response as a function of pinning-site concentration over a large portion of magnetic-field--temperature space. We have found the following: (i) The curves of effective pinning energy [ital U][sub eff] versus current density [ital J] reveal a diverging behavior of [ital U][sub eff]([ital J]) in the low-[ital J] regime. This supports the existence of a vortex-glass state, and is a signature of a vanishing resistance as the current density approaches zero. (ii) Both the [ital U][sub eff] and the [ital J] values obtained from magnetic hysteresis loops were observed to increase with Y 2:1:1 concentration. The appearance of the butterfly-shaped (or fishtail'') hysteresis loops indicates a [ital J][sub [ital c]] that is an increasing function of [ital H] (or [ital B]). Moreover, it has been demonstrated that the additional pinning leads to an increase in [ital U][sub eff] in an [ital H]-[ital T] region in which the butterfly is developed.

• OSTI ID: 6082382
• Journal Information: Physical Review, B: Condensed Matter; (United States), Vol. 48:18; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
MAGNETIC PROPERTIES
COPPER OXIDES
YTTRIUM OXIDES
HIGH-TC SUPERCONDUCTORS
HYSTERESIS
PRECIPITATION
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SEPARATION PROCESSES
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
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360207* - Ceramics
Cermets
& Refractories- Superconducting Properties- (1992-)