Pressure-temperature phase diagram of the heavy-electron superconductor URu2Si2
Pressure-temperature phase diagram of the heavy-electron superconductor URu2Si2
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DOI：
10.1016/j.jmmm.2006.10.008
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发表时间：
2007-03-01
影响因子：
2.7
通讯作者：
Yokoyama, M.
中科院分区：
文献类型：
--
作者：
Amitsuka, H.;Matsuda, K.;Yokoyama, M.
重电子超导体 URu2Si2 的压力-温度相图已通过交流磁化率和弹性中子散射 (NS) 测量进行了重新研究，这些测量是在 Cu-Be 钳式高压池中的小单晶棒（直径 2mm，长度 6mm）上进行的（P < 1: 1GPa）。在环境压力下，该样品显示出迄今为止报道的最弱的反铁磁 (AF) 布拉格反射，对应于类似于 0.011 mu(B)/U 的 mu 体积平均交错矩。在施加压力下，AF 散射强度在低温下 P 处呈现急剧增加，类似于 0.7GPa。 0.7 GPa 以上的 AF 散射强度的饱和值对应于类似于 0.41 mu(B)/U 的 mu(o)，这与我们之前 NS 测量中观察到的 1.5 GPa 以上的值（类似于 0.39 mu(B)/U）非常吻合。 AF 相的演化极大地抑制了超导性，表明超导态仅与隐序相共存。还讨论了转变温度为 T-1(*) = 120(5)、T-2(*) = 36(3) 和 T-3(*) = 16: 5(5) K 的寄生铁磁和/或反铁磁相的存在及其与低 T 有序相的关系。 (c) 2006 Elsevier B.V. 保留所有权利。
The pressure-temperature phase diagram of the heavy-electron superconductor URu2Si2 has been reinvestigated by AC-susceptibility and elastic neutron-scattering (NS) measurements performed on a small single- crystalline rod (2mm in diameter, 6mm in length) in a Cu-Be clamp-type high- pressure cell (P < 1: 1GPa). At ambient pressure, this sample shows the weakest antiferromagnetic (AF) Bragg reflections reported so far, corresponding to the volume-averaged staggered moment of mu similar to 0.011 mu(B)/U. Under applied pressure, the AF scattering intensity exhibits a sharp increase at P similar to 0.7GPa at low temperatures. The saturation value of the AF scattering intensity above 0.7 GPa corresponds to mu(o) similar to 0.41 mu(B)/U, which is in good agreement with that (similar to 0.39 mu(B)/U) observed above 1.5 GPa in our previous NS measurements. The superconductivity is dramatically suppressed by the evolution of AF phase, indicating that the superconducting state coexists only with the hidden order phase. The presence of parasitic ferro- and/or antiferromagnetic phases with transition temperatures T-1(*) = 120(5), T-2(*) = 36(3) and T-3(*) = 16: 5(5) K and their relationship to the low-T ordered phases are also discussed. (c) 2006 Elsevier B.V. All rights reserved.