Non monotonic variation of the critical current as a function of the magnetic field in a heavily cold worked type ii superconductor

Publisher Website
Google Scholar
Abstract
We propose a pinning model accounting for the appearance of a large region where dJc/dH is positive. This model is based on the existence of two different mechanisms of pinning. The experimental results obtained on a sample of Nb-1 % Zr are compared with the theoretical predictions of our model : temperature dependence of Hp, the field for which the critical current exhibits a minimum, and influence of the critical parameter αc. The assumptions involved in the calculations are well supported by electron microscopy observations, and we obtain qualitative agreement between theory and experiments