不同金属位置掺杂的YBCO体系中两个结构块和超导电性的关联

Interaction Between Two Structural Blocks and Superconductivity in Different-Metal-Site Doped YBCO

根据块模型,对不同掺杂量的YBa2Cu3-xNixOy,Y1-xPrxBa2Cu3Oy和YBa2-xLaxCu3Oy体系内两个结构块的结合能进行了计算,研究了结合能和超导电性的关系。结果显示:3个体系中随掺杂量的变化,块间结合能和超导转变温度之间存在有趣的关联,即:随着掺杂量的增加,块间结合能增大,超导转变温度减小。同时在YBa2Cu3-xNixOy,Y1-xPrxBa2Cu3Oy和YBa2-xLaxCu3Oy体系中虽然有相似的结论,但也有源于不同元素在不同位置掺杂的差别。这不仅说明钙钛矿块和岩盐块间的相互作用在超导电性中起重要要作用,而且说明不同元素在不同位置的掺杂对超导电性有不同的影响。

The combinative energy between two structural blocks in YBa2Cu3-xNixOy, Y1-xPrxBa2Cu3Oy and YBa2-xLaxCu3Oy, with different x concentration, has been calculated on the basis of a block model. The relationship between the combinative energy and superconductivity has been investigated. The results indicate that there is an interesting correlation among the combinative energy, the Tc value, and the dopants. Although there are some similarities in correlation among YBa2Cu3-xNixOy, Y1-xPrxBa2Cu3Oy and YBa2-xLaxCu3Oy, there are also some notable differences which may originate from different elements substitution for different sites. The results not only suggest that the interaction between perovskite-type and rocksalt-type blocks plays an essential role in high-Tc superconductivity, but also give us some clues of the influence on superconductivity of different elements substitution for different sites.