| 摘要 |
PURPOSE:To give an equal formation phase with oxide superconductors in powder and bulky body or the like to an oxide superconducting wire by setting treating temperature in a heat treatment process lower by 5 deg.C to 25 deg.C than the temperature at which an aimed abundance fraction of superconductive phase becomes maximum in a phase diagram of an element series composing the oxide superconductor. CONSTITUTION:A raw material powder containing constitutional elements of an oxide superconductor in an specific ratio is filled into a metallic sheathing tube and heat- treated in an atmosphere within the range of 15% to 30% of oxygen partial pressure. For wire of an oxide superconductor of Bi series or Pb added Bi series, a preferable heat treatment condition is within the range of 835 deg.C to 850 deg.C in temperature. In accordance with a phase diagram, the heat treatment condition to maximize an abundance fraction of a high Tc phase (2223 phase) of the Bi series oxide superconductor is in the temperature range of 850 deg.C to 860 deg.C in the atmosphere, the optimum temperature of the heat treatment for the wire having the metallic sheathing tube, however, is in the range lower by 10 to 15 deg.C than the above temperature range. The heat treatment in the atmosphere of oxygen partial pressure of 15 to 30% is preferable, but it is easily performed in the atmosphere in general because of no need of an atmosphere adjustment. |
