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Significantly enhanced flux pinning in the Bi-substituted TlBa{sub 2}Ca{sub 2}Cu{sub 3}O{sub y} system

Journal Article · · Applied Physics Letters
DOI:https://doi.org/10.1063/1.120030· OSTI ID:543751
; ;  [1]
  1. Department of Physics, Campus Box 390, University of Colorado, Boulder, Colorado 80309-0390 (United States)
We have found that substitution of bismuth into the TlBa{sub 2}Ca{sub 2}Cu{sub 3}O{sub 9} system leads to a high temperature superconductor with significantly greater low temperature flux pinning than that of the other copper oxide superconductors. Bi substitutes at the Tl site up to 20 at.{percent}. The superconducting transition temperature T{sub c} increases from 110 K for x=0.0 to 116 K for x=0.2. Scanning electron microscope (SEM) images reveal a platelike morphology which is highly suitable for powder-in-tube processing. The magnetization{endash}hysteresis loop shows that the Bi-substituted phase has significantly better low temperature flux pinning properties than the pristine Tl cuprate, and exhibits only a weak dependence on temperature and field when compared to that of unsubstituted phase. However, at 77 K the compound has lower J{sub c}, determined magnetically, compared to that of the (Tl,Pb,Bi)Sr{sub 1.6}Ba{sub 0.4}Ca{sub 2}Cu{sub 3}O{sub y} and Y-123 systems. The enhancement of superconducting properties is attributed to an increased coupling between the CuO{sub 2} planes along the {ital c} axis. Substitution of 20{percent} of Bi in TlBa{sub 2}Ca{sub 2}Cu{sub 3}O{sub 9} makes the compound an excellent choice for magnet wire applications at relatively low temperatures. {copyright} {ital 1997 American Institute of Physics.}
OSTI ID:
543751
Journal Information:
Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 16 Vol. 71; ISSN APPLAB; ISSN 0003-6951
Country of Publication:
United States
Language:
English