标题： 不混溶的铜-铌相分离纳米复合薄膜中的超导性 显示英文标题

标题： Superconductivity in im-miscible Cu-Nb phase separated nano-composite thin films

摘要： 粒状薄膜中的超导性由晶粒尺寸和晶间耦合控制。 在由正常金属（N）和超导体（S）随机混合形成的双组分粒状系统中，超导纳米晶粒可能通过S-N弱连接耦合，从而影响网络的超导特性。 我们报告了对不同成分的不混溶Nb-Cu纳米复合薄膜中超导性的研究。 薄膜的显微结构显示存在相分离、紧密排列的Nb和Cu纳米晶粒，其尺寸随成分变化较小。 随着Cu浓度的增加，薄膜的超导转变温度（Tc0）降低，同时上临界磁场（Hc2）和临界电流（Ic）也相应降低。 我们的结果表明，在所有薄膜中都存在超导相涨落，这些涨落不仅影响了薄膜中真正相位相干超导凝聚态的形成温度，还影响了其他超导特性。 显示英文摘要

摘要： Superconductivity in granular films is controlled by the grain size and the inter-grain coupling. In a two-component granular system formed by a random mixture of a normal metal (N) and a superconductor (S), the superconducting nano-grains may become coupled through S-N weak links, thereby affecting the superconducting properties of the network. We report on the study of superconductivity in immiscible Nb-Cu nanocomposite films with varying compositions. The microstructure of the films revealed the presence of phase separated, closely spaced, nano-grains of Nb and Cu whose sizes changed marginally with composition. The superconducting transition temperature (Tc0) of the films decreased with increasing concentration of Cu with a concomitant decrease in the upper critical field (Hc2) and the critical current (Ic). Our results indicate the presence of superconducting phase fluctuations in all films with varying Nb:Cu content which not only affected the temperature for the formation of a true phase coherent superconducting condensate in the films but also other superconducting properties.