| 摘要 |
PURPOSE:To obtain a superconducting bulk material excellent in magnet characteristics and floating force and high compression strength without a melting or rapid cooling process. CONSTITUTION:The yittrium-base superconducting bulk material (18) is obtd. by the following procedure. Source powders of Y2O3, BaCO3, CuO, by molar ratio of 1:2:3 are mixed and pulverized (process 11), calcined (process 12) and again pulverized to obtain oxide powder of YBa2Cu3O7 (process 13). To this powder, Ag powder of 1-50mum average particle size and Y2O3 of 0.5-3.0mum average particle size are mixed and dispersed (process 14), and compacted (process 15). This compacted body is heated at >1000 deg.C and <1200 deg.C to form a half- molten state and futher heat-treated at 1000-900 deg.C for crystal growth to form a 211 phase expressed by the following formula in the compsn (process 16). Then the product is subjected to heat treatment at 600-300 deg.C in an oxygen atmosphere (process 17). YBa2Cu3O7+Y2O3+Ag YBa2Cu3O7+Y2BaCuO5+Ag. |
