Effects of 3.1-MeV proton and 1-GeV Au-ion irradiation on the magnetic flux noise and critical current of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}
- Department of Physics, University of California, Berkeley, California 94720 (United States)
- Bell Laboratories, Lucent Technologies, Murray Hill, New Jersey 07974 (United States)
We have used a dc superconducting quantum interference device to measure the spectral density of magnetic flux noise, {ital S}{sub {Phi}}({ital f}), generated by vortex motion in crystals of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} (YBCO) both before and after irradiation with 3.1-MeV protons and 1-GeV Au ions. In addition, we have studied the effects of irradiation on the critical current {ital J}{sub {ital c}} of the same samples. Both types of irradiation reduced {ital S}{sub {Phi}}({ital f}) at most temperatures and magnetic fields and increased {ital J}{sub {ital c}} at all temperatures and magnetic fields. By measuring {ital S}{sub {Phi}}({ital f}) versus temperature, we extract the distribution of vortex pinning energies, {ital D}({ital U}{sub 0}). Both crystals have peaks in {ital D}({ital U}{sub 0}) near 0.1 eV and 0.2 eV before irradiation, and a much reduced peak near 0.1 eV after irradiation. The noise level after either kind of irradiation was substantially higher than in an unirradiated YBCO film. {copyright} {ital 1996 The American Physical Society.}
- Research Organization:
- Lawrence Berkeley National Laboratory
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 397619
- Journal Information:
- Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 21 Vol. 54; ISSN PRBMDO; ISSN 0163-1829
- Country of Publication:
- United States
- Language:
- English
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