| 摘要 |
PURPOSE:To prevent abnormal expansion, to reduce porosity and to enhance quality by calcining powdery starting material including an alkaline earth metal and a rare earth metal at a prescribed temp. and by press-molding the calcined product under a prescribed pressure. CONSTITUTION:Powdery starting material prepd. by blending a rare earth metal compd. such as Y2O3 with an alkaline earth metal compd. such as BaCO3, etc., is calcined at 750-950 deg.C to remove the volatile component in the starting material. The calcined product is pressmolded under <=500kgf/cm<2> pressure, heated to 900-1,000 deg.C at 0.4-0.6 deg.C/min heating rate, held for about 15hr, cooled to 500 deg.C at 0.4-0.6 deg.C/min cooling rate and subjected to furnace cooling to produce superconducting ceramics represented by the formula (where A is an alkaline earth metal, R is a rare earth metal and 0<x<7). |
