抄録
The effect of annealing, which was carried out at 300°C-845°C for 24h in air, on the superconductivity in the Bi-Pb-Sr-Ca-Cu-O ceramics was investigated. The tailing phenomenon was observed in the R-T curves for all samples annealed at temperatures in the range of 600°C to 825°C though the as-sintered sample and the samples annealed at 300°C, 400°C and 845°C exhibited a sharp superconducting transition above 100K. In addition, a relatively large unknown peak was observed at 2θ=17.9° close to the main peak(2θ=17.6°) of the Ca2PbO4 phase in the X-ray diffraction pattern of the sample annealed at 700°C. From the above results, it is supposed that the tailing phenomenon in the R-T curve is closely related to an appearance of the unknown peak.
