Using capacitance torque magnetometry, hysteresis loops were measured on a Pb-ion irradiated DyBa2Cu3O7-δ single crystal as a function of magnetic field, temperature and angle Θ between the field direction and the c axis of the sample. The superconducting current densities, jc (T, B, Θ), determined using the extended Bean model, show a clear fishtail effect at temperatures above 30 K despite the large enhancement of jc due to the columnar tracks. The enhancement of jc due to irradiation was magneto-optically determined to jc(φt)/jc(0) = 10 at T = 30 K. The pinning energy U0 is, however, only slightly increased by the irradiation. Our measurements indicate clearly that the fishtail effect is a general feature of the high-Tc superconductors and not related to a special arrangement of pinning centres.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering