Oxide superconducting wire,method of preparing the same, and oxide superconducting stranded wire and conductor employing the same

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 (10) consists of a plurality of filaments (1) extending along the longitudinal direction of the wire (10) in the form of ribbons, and a stabilizer matrix (2, 3) covering the filaments (1). The aspect ratio of the width to the thickness of each filament (1) is 4 to 40, and the thickness of each filament (1) is 5 to 50 mu m. A section of the wire (10) is in a circular or substantially circular shape. The wire (10) exhibits a critical current density of at least 2000 A/cm<2> at a temperature of 77 K with no application of a magnetic field. It is preferable that the plurality of filaments (1) are substantially rotation-symmetrically arranged with respect to the center of the wire (10). It is also preferable that a hexagonal-prismatic stabilizing matrix (2) is provided at the center of the wire (10) and the plurality of filaments (1) covered with the stabilizer matrix (3) 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.