| 摘要 |
PURPOSE:To obtain an oxide superconducting material having a high superconductivity transition temp. with good reproducibility by sintering a material contg. Tl, Ba, Ca, Cu and O under specified conditions. CONSTITUTION:The powders of Tl2O3, BaCO3, CaCO3 and CuO having >=99.5% purity are used and weighed so that the ratio of BaCO3, to CuO is controlled to Ba:Cu=1:1. The powders are wet-crushed, mixed, then heated and dried. The obtained powder is calcined at 900 deg.C for 5hr in the air, then crushed, heated and dried to obtain a BaCuO2 powder. CaCO3 and CuO are then mixed in the same way, and the mixture is calcined at 950 deg.C to synthesize a Ca2CuO3 powder. The BaCuO2 powder, Ca2CuO3 powder, Tl2O3 powder and CuO powder are weighed so that the molar ratio is controlled to T:Ba:Ca:Cu=1:1:3:3, crushed and mixed, and the obtained powder is press-formed. The formed body is sintered at 720-840 deg.C for >=8hr. |
