Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Magnetic relaxation and critical current density limited by flux creep in Bi sub 1. 6 Pb sub 0. 4 Sr sub 1. 6 Ca sub 2 Cu sub 2. 8 O sub x ( T sub c =115 K) and YBa sub 2 Cu sub 3 O sub 7 minus x

Journal Article · · Physical Review (Section) B: Condensed Matter; (USA)
; ;  [1]
  1. Department of Metallurgical Engineering and Materials Science and Mellon Institute, Carnegie Mellon University, Pittsburgh Pennsylvania 15213 (US)
We have investigated the magnetization behavior of Bi{sub 1.6}Pb{sub 0.4}Sr{sub 1.6}Ca{sub 2}Cu{sub 2.8}O{sub {ital x}} (Bi 2:2:2:3) and YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} (Y-Ba-Cu-O) as a function of field, temperature, and time. We find a logarithmic time decay in both zero-field-cooled magnetization and remanent magnetization, consistent with the Anderson-Kim flux-creep model with activation energies of {ital U}{sub 0}/k=700 K (0.06 eV) for Bi 2:2:2:3 and {ital U}{sub 0}/k=1700 K (0.15 eV) for Y-Ba-Cu-O in an applied field of 1 kOe. Measured activation energies remain essentially temperature independent for {ital T}/{ital T}{sub {ital c}} less than 0.6 while {ital J}{sub {ital c}}(T) decays rapidly as a result of the relatively small {ital U}{sub 0}.
OSTI ID:
5650415
Journal Information:
Physical Review (Section) B: Condensed Matter; (USA), Journal Name: Physical Review (Section) B: Condensed Matter; (USA) Vol. 40:7; ISSN 0163-1829; ISSN PRBMD
Country of Publication:
United States
Language:
English