Observation of vortex distribution in samples of Bi-2223 Ag-sheathed tapes with and without uranium doping by means of the high-resolution Bitter method

Authors

S. Ohshima, Yamagata University, Japan
K. Ujiie, Yamagata University, Japan
T. Kawai, Yamagata University, Japan
K. Moriai, Yamagata University, Japan
H. Yamada, Yamagata University, Japan
D. G. Marinaro, University of Wollongong
S. X. Dou, University of WollongongFollow

RIS ID

9648

Publication Details

This article was originally published as: Ohshima, S, Ujiie, K, Kawai, T et al, Observation of vortex distribution in samples of Bi-2223 Ag-sheathed tapes with and without uranium doping by means of the high-resolution Bitter method, IEEE Transactions on Applied Superconductivity, June 2003, 13(2)3, 2953-2955. Copyright IEEE 2003.

Abstract

We examined the distribution of vortices in both Bi-2223 Ag-sheathed tape and U-doped Bi-2223 Ag-sheathed tape applying the high-resolution Bitter method. In the low temperature region (T/spl Lt/T/sub c/), we found that the vortices in the undoped Bi-2223 Ag-sheathed tape developed into either a triangular arrangement or a heterogeneous arrangement along the grain boundaries of the Ag sheath, which form weak pinning centers. The vortex distribution for U-doped Bi-2223 samples was slightly different from the distribution for the undoped material. We observed some movement of the vortices in both the U-doped and the undoped Bi-2223 Ag-sheathed tapes at 50 K. At higher temperatures, T>75 K, the vortices in the Bi-2223 tapes moved even faster so that no deposition pattern, indicating the location for vortices, formed.