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着重讨论了准静水冷压对Bi系高温超导材料超导电性的影响,并分析了经冷压-退火处理后超导电性的改善情况。准静水冷压处理后,Bi系超导材料晶粒间界连接发生显著退化,晶粒内部产生大量缺陷,由此导致了宏观超导电性的退化。冷压造成了体密度的极大提高和一定的晶粒择优取向。这些现象主要是由于准静水压下剪切应力的作用。退火后,晶界连接得到很大加强,部分缺陷消失或形成堆错使材料各项性能均获改善。Jc(77K,零场)较初始样品有大幅度提高,达约1600A/cm2。此外还考察了静水压The effects of quasi-hydrostatic pressure treatments on the Bi-system superconductors were investigated The cold-pressing treatments seriously weakened the inter-granular weaklinks and induced a large number of intragranular defects, resulting in the deterioration of the suprcon-ducting properties. The targe increase in the bulk density and the orientation of the superconducting grains were also observed in the cold-pressed samples. These drastic changes of superconductivity were mainly due to the shear stress under quasi-hydrostatic pressure. The post annealing treatments greatly enhanced the weaklinks and caused the partial recovery and the agglomeration of some defects. By coldpressing-annealing method, Jc (77 K, zero field) was raised to about 1600A/cm2. The pressure dependence of Tc under hydrostatic pressure was also investigated and dTc/dp was found to be 1.4K/GPa.
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