Multifilamentary oxide superconducting wire and coil formed by the same.

摘要

Provided is a superconducting coil, obtained from a wire consisting essentially of an oxide superconductor covered with silver or a silver alloy, which has sufficient strength with substantially no deterioration of superconductivity in a high magnetic field. An oxide superconducting coil is formed by winding a superconducting multifilamentary wire (10) consisting essentially of a plurality of filaments (2) consisting essentially of an oxide superconductor and a stabilizing material (1), consisting of silver or a silver alloy, covering the filaments (2). Superconducting phases of the filaments (2) are substantially rendered monophasic, and c-axes thereof are strongly oriented along the thickness of the wire. Crystal grains of the superconductor forming the filaments (2) are in the form of flakes extending longitudinally along the wire, while the same are bonded to each other. In a section of the wire, a ratio obtained by dividing a sectional area occupied by the silver or the silver alloy by that occupied by the filaments is not more than 3. In a magnetic field of at least 10 T, the coil exhibits a critical current value which is at least 60 % of that exhibited by the wire itself forming the coil.