Abstract The effects of Ta substitutions on the superconducting properties of (Tl1-xTax)(BaSr)CaCu2O7 for x = 0, 0.1, 0.2 and 0.3 are reported. X-ray diffraction patterns showed a single Tl-1212 phase for the x = 0 samples. Unreacted Ta2O5 peaks were observed in all Ta substituted samples. The electrical resistance versus temperature curves showed metallic normal state behavior. The transition temperature and maximum intergrain Josephson current decreased for x = 0. 1 and 0.2 but increased for x = 0.3 samples. The intergranular critical current density, Jc at the peak temperature, Tp of the imaginary part of the susceptibility was between 15 and 22 A cm-2. The x = 0.3 samples showed an increase in Tp indicating the enhancement of inter-grain coupling. The Josephson coupling energy, EJ showed that the intergranular coupling and flux pinning energy decreased for x ≤ 0.2 but increased for x = 0.3 samples. The roles of Ta2O5 in the Tl(BaSr)CaCu2O7 superconductors are discussed.

中文翻译：

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Ta 取代 (Tl1Ta )(BaSr)CaCu2O7 超导体的交流磁化率和电学特性 (x = 0 – 0.3)

摘要 报道了当 x = 0、0.1、0.2 和 0.3 时，Ta 取代对 (Tl1-xTax)(BaSr)CaCu2O7 超导性能的影响。X 射线衍射图显示 x = 0 样品的单一 Tl-1212 相。在所有 Ta 取代的样品中均观察到未反应的 Ta2O5 峰。电阻与温度曲线显示金属正常状态行为。转变温度和最大晶间约瑟夫森电流在 x = 0. 1 和 0.2 时降低，但在 x = 0.3 样品时增加。峰值温度下的晶间临界电流密度 Jc，磁化率虚部的 Tp 介于 15 和 22 A cm-2 之间。x = 0.3 样品显示 Tp 增加，表明晶粒间耦合增强。约瑟夫森耦合能量，EJ 表明，当 x ≤ 0.2 时，晶间耦合和磁通钉扎能降低，但 x = 0.3 样品时增加。讨论了 Ta2O5 在 Tl(BaSr)CaCu2O7 超导体中的作用。