| 摘要 |
PURPOSE:To obtain a superconductor hardly affected by conditions in production by rendering a specified compsn. consisting of Pb, Sr, prescribed elements, Ce, Cu and O. CONSTITUTION:This superconductor is represented by the formula (where betais one or more kinds of elements selected among La, Nd, Sm, Eu, Gd, Dy, Ho and Y, in the case of two or more kinds of elements, Nd, Sm, Eu and Cd are made to preferably account for >=80% of the total amt., 1.9<p<2.1, 9<q+r+s<4.1, 0<=s<0.8, 2.01<y-p-q-1.5r-2s-0.5<2.25 and 9.5<y<2.25). This superconductor is produced as follows: powders of oxides of the constituent elements or precursors of the oxides are mixed so as to satisfy relation among p, q, r and s in the formula and the mixture is pulverized, fired at 700-1,000 deg.C, pulverized, mixed again and molded into a desired shape. This molded body is put in a furnace, fired at 900-1,050 deg.C for 1-40hr and further heat-treated at 300-700 deg.C under >=1 atm pressure. |
