Flux pinning by discontinuous columnar defects in 74 MeV Ag-irradiated YBa2Cu3O7 coated conductors

摘要

Linear damage tracks are created in production-quality YBCO coated conductors by irradiation with 61-74 MeV Ag ions. The ion tracks are observed by transmission electron microscopy to be elongated but discontinuous. The in-field transport critical current (I-c) is enhanced significantly for fields applied parallel to the irradiation direction with a broad peak appearing in the magnetic field-angle dependence of the critical current, coinciding with the irradiation direction. The zero-field I-c is typically reduced somewhat, however annealing at 200 degrees C partially restores this and enhances the in-field I-c even for field parallel to the irradiation direction. Lower energies tend to produce a weaker peak, but also retain the zero-field I-c to a greater extent, consistent with a trend of greater discontinuity in the ion tracks. reserved.