Non-magnetic to Magnetic Transition under High Pressure in Narrow-Gap Semiconductor □-US_2
Non-magnetic to Magnetic Transition under High Pressure in Narrow-Gap Semiconductor □-US_2
复制标题
窄带隙半导体高压下的非磁性到磁性转变□-US_2
DOI：
10.1143/jpsjs.80sa.sa103
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
et al
中科院分区：
文献类型：
--
作者：
N.Tateiwa;Y.Onuki;et al
我们在一台商用SQUID磁强计上，用活塞圆筒和压头式磁池测量了铀硫族化合物β-US_2在2.42GPa高压下的磁化强度。该化合物是一种窄隙半导体，在1巴下，磁性不低于0.3 K。在高压下的电阻率测量的先前的研究建议的压力诱导相的外观超过2 GPa。在这项研究中，人们发现，铁磁状态是诱导高于1 GPa。得到了压力相图。0 K时的自发磁矩值小于0.1 μB/U，表明压力诱导相是一种非常弱的铁磁态。考虑到β-US 2的CEF单重基态，我们认为铁磁态是Pr_3Tl等镨系化合物中常见的“感生磁相”。根据平均场理论对实验结果进行了讨论。
We have measured the magnetization of an uranium chalcogenide compound β-US2under high pressure by piston cylinder and indenter type cells up to 2.42 GPa in a commercial SQUID magnetometer. The compound is a narrow-gap semiconductor that does not order magnetically down to 0.3 K at 1 bar. The appearance of a pressure-induced phase above 2 GPa was suggested by a previous study with the electrical resistivity measurement under high pressure. In this study, it was found that a ferromagnetic state is induced above 1 GPa. The pressure phase diagram were obtained. The values of the spontaneous magnetic moment at 0 K are less than 0.1 µB/U, suggesting that the pressure-induced phase is a very weak ferromagnetic state. Considering the CEF singlet ground state in β-US2, it is suggest that the ferromagnetic state is an “induced-magnetic phase” often observed in some praseodymium compounds such as Pr3Tl. The experimental results are discussed in terms of the mean field theory.