Abstract: Adhesiveness between a metallic substrate and a metal oxide layer is made to increase. A superconducting thin film (1) includes a metallic substrate (10), a metallic layer (22) that is formed on a main surface of the metallic substrate (10) and includes a metal element capable of being passivated as a main component, a metal oxide layer (24) that is formed on the metallic layer (22) and includes the passivated metal element as a main component, and a superconducting layer (40) that is formed on the metal oxide layer (24) directly or through an intermediate layer and includes an oxide superconductor as a main component.

Abstract: Disclosed is a low-cost metal substrate which is resistant to high-temperature oxidation, has excellent strength, is non-magnetic and is ideal for a high-temperature superconducting wire to be used at or lower than liquid nitrogen temperature. Austenitic stainless steel containing 0.4 weight or more of nitrogen is used as the metal substrate for the superconducting wire. After heat treatment of 700 to 950° C. in the high-temperature superconducting layer formation step is carried out, the metal substrate has an extremely high 0.20 proof stress at liquid nitrogen temperature.

Abstract: A superconductor wire comprising a plurality of Nb--Ti superconductor filaments embedded in a copper matrix made of a copper alloy other than a two element copper alloy selected from the group consisting of a Cu--Ni alloy, a Cu--Sn alloy and a Cu--Mn alloy, wherein the resistivity (Z) at room temperature of the copper matrix is 2.times.10.sup.-8 .OMEGA.m to 65.times.10.sup.-8 .OMEGA.m, and the distance between superconductor filaments is not less than 0.0625.times.1/.sqroot.Z nm. The superconductor wire has a high critical current density, a small AC loss and improved workability.