| 摘要 |
PURPOSE:To obtain a Bi-base superconducting material excellent in Jc characteristic and consisting essentially of a Bi2212 phase at the time of producing a Bi-base superconducting material by a partial melting method by controlling the oxygen partial pressure in an atmosphere under specified conditions. CONSTITUTION:A raw material powder contg. Bi, Sr, Ca and Cu is partially melted in an atmosphere with the oxygen partial pressure controlled to 0.001-0.05atm at a temp. lower than 855 deg.C and higher than the m.p. of a Bi2212 phase in the atmosphere with the oxygen partial pressure, and then the oxygen partial pressure is increased at the rate of <=0.01atm/hr to grow the crystal of Bi2212 phase. The temp. in a furnace is preferably kept at the partial melting temp. when the oxygen partial pressure is increased but need not be kept constant, and the temp. is kept at a temp. lower than 855 deg.C and higher than the m.p. of the Bi2212 phase (the m.p. at the initial oxygen partial pressure in the furnace). |
