PURPOSE: To enable O2 feed to a Cu-containing oxide superconductor film in heating treatment carried out at low temperature in short time and make it possible to prevent deterioration of the superconducting film during heating treatment, by preliminarily heating the Cu-containing oxide superconductor film under low O2 partial pressure.
CONSTITUTION: An oxide superconductor substance containing copper, e.g., Y1Ba2Cu3 oxide film is formed on a substrate of Mgo, etc., and the film is preliminarily heated in atmosphere of ≤1Torr, preferably ≤0.1Torr oxygen partial pressure at ≥400°C, e. g. 920°C for 20min. Then the film is subjected to heat treatment in the atmosphere of ≥50Torr, especially ≥100Torr oxygen partial pressure, suitably ≥500°C, e.g., at 850°C for 30min to provide the oxide superconductor film. Critical temperature and critical electric current density of the copper-containing oxide superconductor, e.g., Y1Ba2Cu3 oxide superconductor film are each 89K and 1.9×105.
UNO NAOKI
ENOMOTO KENJI
HARA CHIKUSHI
NOZAKI OKAYA
OGAWA KIYOSHI
KURIHARA TAKESHI
