抄録
A single phase powder with the composition of Bi1.8Pb0.4Sr2.0Ca2.0Cu3.2Oy was sintered with the small amount of Ag2O or compositional oxides. The bulk density, microstructure and superconductive characteristics of the sintered specimens were examined to investigate the effect of the additive oxides on the sinterability and superconducting properties. The bulk density was of 4.3-4.6g/cm3 for the sintered specimens with 0.05-0.1mol addition. Their resistivity curves were divided into three groups, i.e. (a) without additive, Bi2O3 or PbO, (b) SrO, CaO or CuO and (c) Ag2O. From SEM photographs it was observed that the sintered specimens were composed of the three main layer parts consisting of surface layer, orientated layer, and center layer part with disordered orientation. The thickness of the disordered layers in the center part decreased with decreasing the thickness of the specimens. The excellent result of Jc (77K) was shown by the sintered specimen with 0.1mol addition of SrO.
