For AC loss reduction in Bi2223 tapes subjected to
an AC external magnetic field, twisting the superconducting
filaments and/or introducing oxide layers as highly resistive
barriers around each filament are required. However, the
structure of barrier tape becomes very complex and longitudinal
uniformity of both transport property and tape structure could be
easily deteriorated. To improve the current transport capability
and its longitudinal uniformity for barrier tape for AC use, simple
and non-destructive techniques to characterize them should be
indispensable. In this paper, we examined the self-field
distributions for Bi2223 tapes with oxide barriers carrying DC
transport current by a scanning Hall-probe microscopy (SHM).
Non-twisted and twisted 19-filamentary tapes with SrZrO3 +
Bi2212 barriers were prepared by powder-in-tube process. The
distributions of self-field in perpendicular to the broader face of a
tape carrying DC current below critical current Ic was measured
at 77 K by SHM with an active area of 50 μm × 50 μm, at 0.5 mm
away from the tape surface. Based on the measured self-field
distributions, longitudinal non-uniformity of transport properties
and the presence of local defects to obstruct the current transport
in barrier tapes were investigated.
雑誌名
IEEE Transactions on Applied Superconductivity
巻
21
号
3
ページ
2820 - 2823
発行年
2011-06
出版者
IEEE
ISSN
1051-8223
DOI
10.1109/TASC.2010.2091241
権利
This is the author's version of the work. Copyright (C) 2011 IEEE. IEEE Transactions on on Applied Superconductivity, vol.21, no.3, Pages 2820-2823. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.