利用原位电阻测量、热重分析、电镜观察和电子探针等多种实验手段研究了Ｂｉ_（１．６）Ｐｂ_（０．４）Ｓｒ_２Ｃａ_２Ｃｕ_３Ｏ_（１０＋δ）（下称ＢＰＳＣＣＯ）超导材料在不同温度（６５０—８００℃）和不同氧分压（氧气、空气和氮气）下热处理过程中结构变化及其对超导电性的影响，实验结果表明，在稍高氧分压下退火，２２２３相中的Ｐｂ￣（＋２）离子将失稳析出体外，生成类Ｃａ_２ＰｂＯ_４杂相，导致电阻率和重量增加，其调制结构由纯Ｐｂ型（ｑ＝βｂ）逐渐变为纯Ｂｉ型（ｑ＝βｂ＋ｃ），在低氧分压下退火，类Ｃａ_２ＰｂＯ_４杂相将分解，整个过程基本可逆．此外还发现，适度析出类Ｃａ_２ＰｂＯ_４杂相，２２２３母相的超导转变温度将增高，材料的电传输特性亦将得到改善．
The annealing effects on the Pb-doped BPSCCO 2223 phase were studied by in situ electric resistivity measurement, XRD, TGA, TEM and EPMA. Annealing at hight temperature ranging from 650℃ to 800℃under higher oxygen pressure will incur the precipitaion of a Ca_2PbO_4-modified phase. and the impurity phase would be decomposed upon annealing under lower oxygen pressure. With the formation of the impurity phase, the sample's mass and resistivity are increased. and the modulated structure is changed from pure Pb-type to pure Bi-type. While the impurity is decomposed, the mass and the resistiviey of the sample are decreased. and the modulated structure is back to original Pb-type. In addition, the proper amount of precipitation of the Ca_2PbO_4-modified phase has a positive influence on both superconductivity and the weak links between the superconducting grains.
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