| 摘要 |
PURPOSE:To obtain a material having a superconducting critical temp. higher than the boiling point of liquid nitrogen by burning a starting raw material at a temp. of the partial melting temp. or below and forming a composition consisting of Pb, Ba, rare earth elements (RE), Ca, Cu, and O and represented by the prescribed formula. CONSTITUTION:A starting raw material consisting, e.g. of BaCO3, Y2O3, CuO, CaCO3, and PbO is prepared. This raw material is burned at a temp. of its partial melting temp. or below in an inert gas, in a partial pressure of oxygen as low as <= at least 2% partial pressure of oxygen, or in vacuum. By this method, a composition represented by a compositional formula Pb2Ba2(RE1-xCax) Cu3OY (where the amount (x) of substitution of Ca is regulated to 0.3-1) can be formed. Further, the above RE is selected from a group consisting of Y, La, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, and Lu. |
