Method of preparing oxide superconducting wire

摘要

An oxide superconducting wire having a circular or substantially circular sectional shape and exhibiting a high critical current density comparable to that of a tape-shaped wire is provided. The oxide superconducting wire consists of a plurality of filaments extending along the longitudinal direction of the wire in the form of ribbons, and a stabilizer matrix covering the filaments. The aspect ratio of the width to the thickness of each filament is 4 to 40, and the thickness of each filament is 5 to 50 mum. A section of the wire is in a circular or substantially circular shape. The wire exhibits a critical current density of at least 2000 A/cm2 at a temperature of 77 K with no application of a magnetic field. It is preferable that the plurality of filaments are substantially rotation-symmetrically arranged with respect to the center of the wire. It is also preferable that a hexagonal-prismatic stabilizing matrix is provided at the center of the wire and the plurality of filaments covered with the stabilizer matrix are arranged on each side surface thereof in a layered manner. A flat stranded wire having low ac loss can be formed by such wires.