Correlation between Superconductivity and Ferromagnetism in UGe2
Correlation between Superconductivity and Ferromagnetism in UGe2
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UGe2 中超导性与铁磁性的相关性
DOI：
10.1143/jpsj.74.855
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发表时间：
2005
影响因子：
1.7
通讯作者：
N. Sato
中科院分区：
文献类型：
--
作者：
Hiroyuki Nakane;G. Motoyama;T. Nishioka;N. Sato
我们测量了铁磁体 UGe 2 的交流磁化率，该铁磁体在铁磁相内的高压下表现出超导性。众所周知，铁磁相分为两相，因此存在两个临界压力，即未知相变终止的 P X ～12 kbar 和居里温度被抑制为零的 P FM ～16 kbar。我们在 P X 附近观察到以下特征：超导转变温度与压力图的不连续性、最大超导体积分数与 P FM 附近的小体积分数形成鲜明对比，以及上临界磁场的初始斜率显着增强（超过 200 kOe/K）。这些结果表明超导性与 P X 直接相关。因此我们得出结论，是临界点 P X 而不是 P FM 在超导性的出现中起着至关重要的作用。
We measured the ac magnetic susceptibility of the ferromagnet UGe 2 that exhibits superconductivity at high pressures within a ferromagnetic phase. It is known that the ferromagnetic phase is separated into two phases and thus there are two critical pressures, namely, P X ∼12 kbar at which an unknown phase transition terminates and P FM ∼16 kbar at which a Curie temperature is suppressed to zero. We observed the following features in the vicinity of P X : the discontinuity in the plot of superconducting transition temperature versus pressure, the maximum superconducting volume fraction in contrast to the small volume fraction near P FM , and the markedly enhanced initial slope of the upper critical magnetic field (exceeding 200 kOe/K). These results indicate that the superconductivity directly correlates with P X . We conclude therefore that it is the critical point P X , rather than P FM , that plays a crucial role in the appearance of the superconductivity.