| 摘要 |
PURPOSE:To produce a superconducting material having high critical temp., high purity, and uniform compsn. by exposing a molded body of fluorides of constituting elements of a superconducting material to oxidizing atmosphere and forming a specified compound oxide on the surface of the molded body. CONSTITUTION:Each fluoride or compound fluoride 3 of (A) >=one element selected from the group IIa of the periodic table, (B) >=one element selected from the group IIIa of the periodic table, and (C) >=one element of the groups Ib, IIb, IIIb, IVb, and VIIIa of the periodic table is charged to a crucible 2 mounted in a heating furnace 1. After melting and mixing the charged materials, the materials are poured into a mold 4 and cooled by allowing to stand to obtain thus a molded body of compound fluoride 3. The molded body 3 is then held in a vessel 6 mounted in a heating furnace 1 and melted by heating. The melt is extruded through a nozzle 5, then exposed to oxidizing atmosphere. Thus a compound oxide expressed by the formula (wherein 1<=w; x<=5; 1<=y<=15; 1<=z<=20) is formed on at least the surface of the molded body. |
