Influence of non-uniform J<Subscript>c</Subscript> distributions on flux jumps in high-temperature superconductors

The influence of non-uniform J<Subscript>c</Subscript> distributions on flux jumps in high-temperature superconductors is investigated with the simplified models in the form of a composite superconducting slab consisting of different pinning regions. The magnetization loops and flux jumps for the simplified models are calculated with the modified recursion formulas which could predict the flux-jump fields. The valid ranges of the temperature and sweep rate for B<Subscript>fj1</Subscript> are specified and the fields of the subsequent jumps after the first flux jump of the inhomogeneous models are obviously lower than that of the homogeneous models. The results indicate that flux jump instability could be stimulated by non-uniform J<Subscript>c</Subscript> distributions and with the increase of the discrepancy of J<Subscript>c</Subscript> between different pinning regions the instability also increase. Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2008