Flux-pinning energy and critical current density in Y{sub 1{minus}{ital x}}Pr{sub {ital x}}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} detwinned single crystals
- Department of Physics and Materials Research Laboratory, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801 (United States)
We have measured the magnetic relaxation of four detwinned single crystals of Pr-doped Y{sub 1{minus}{ital x}}Pr{sub {ital x}}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} with {ital x}=0, 0.1, 0.2, and 0.3, in a magnetic field of 0.5 T applied parallel to the {ital c} axis of each sample. We have calculated the effective flux-pinning energy {ital U} for each sample using the Anderson-Kim (AK) model of thermally activated flux creep, Maley{close_quote}s procedure, collective-pinning theory, and the pinning energy distribution model of Hagen and Griessen. Analysis in terms of the AK model, shows that for {ital T}/{ital T}{sub {ital c}}{lt}0.45, {ital U} exhibits a weak dependence on Pr concentration, whereas for {ital T}/{ital T}{sub {ital c}}{gt}0.45, {ital U} shows a clear maximum at {ital x}=0.2. Maley{close_quote}s procedure indicates that the {ital J} dependence of {ital U} is highly nonlinear, and therefore the results from the AK model should be interpreted with caution. However, Maley{close_quote}s procedure also suggests that the pinning energy is optimally enhanced for approximately 10{percent} Pr doping. In addition, we have measured magnetic hysteresis loops for each sample at {ital T}/{ital T}{sub {ital c}}=0.1, 0.5, and 0.8. We find that the samples exhibit a strong {open_quote}{open_quote}fishtail{close_quote}{close_quote} effect, and, of particular interest, the sample with {ital x}=0.1 shows two magnetization peaks in addition to the zero-field peak. {copyright} {ital 1996 The American Physical Society.}
- OSTI ID:
- 388338
- Journal Information:
- Physical Review, B: Condensed Matter, Vol. 54, Issue 17; Other Information: PBD: Nov 1996
- Country of Publication:
- United States
- Language:
- English
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