Effect of distribution of flux pinning strength on reversibility line and vortex glass-liquid transition line in a Bi-2212 tape wire

The irreversibilty line and the vortex glass-liquid transition line are investigated for a dip-coated Bi-2212 superconducting tape. These two characteristic lines are also analyzed using the flux creep-flow model in which the distribution of the flux pinning strength is assumed. These results are compared with the previous results for a silver-sheathed Bi-2212 tape. Good agreements were not obtained simultaneously between the experiment and the theory for the two characteristic lines in the dip-coated tape, although the theory explained the experimental results well in the silver-sheathed tape. This seems to be ascribed to the peculiar distribution of the flux pinning strength with two peaks due to a percipitation of an impurity phase in the present dip-coated tape specimen. (C) 1999 Elsevier Science B.V. All rights reserved.