NMR study of uranium-based ferromagnetic superconductors

为了研究f-电子系统中磁性与超导电性之间的关系，对几种不同条件合成的UCoGe样品进行了NMR测量。我们发现，随着剩余电阻比（RRR）的增加，样品中铁磁相的体积也随之增加。由于体测量表明超导相的体积也随着RRR的增加而增加，NMR结果表明，铁磁有序是UCoGe超导性发生的必要条件。

In order to investigate the relationship between magnetism and superconductivity in f-electron systems, NMR measurements have been performed in several UCoGe samples synthesized with different conditions. We have found that the volume of ferromagnetic phase in the samples increases with increasing their residual resistance ratio (RRR). Since bulk measurements indicate that the volume of superconducting phase also increases with increasing RRR, the NMR result suggests that the ferromagnetic ordering is essential for the occurrence of superconductivity in UCoGe.