Magnetic-Field-Induced Metallic State in □-US_2
Magnetic-Field-Induced Metallic State in □-US_2
复制标题
□-US_2 中的磁场感应金属态
DOI：
10.1143/jpsjs.80sa.sa104
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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：
K.Sugiyama;Y.Onuki;et al
β-US 2具有正交晶系结构，在低于80 K的温度下，其电性能由金属态转变为绝缘态。为了阐明目前的金属-绝缘体变化，我们进行了磁化和磁阻测量磁场高达50 T。当磁场沿着磁易磁化轴（即[001]方向）时，4.2 K时的磁化在40 T以上达到饱和，在50 T时达到1.75 μB/U。当磁场沿[001]方向沿着施加时，相应的电阻率在4.2 K时从1 × 10 - 3 Ω·cm急剧下降到50 T时的2 ×10-2Ω·cm。在50 T下电阻率的温度依赖性表明通常的金属行为。当5 f-CEF磁矩在50 T的强磁场中被完全极化时，传导电子最有可能从俘获的U位释放。从磁极化子的观点讨论了目前的实验结果。
β-US2with the orthorhombic structure is an interesting compound of which the electrical property is changed from a metallic state to an insulating state at temperatures lower than 80 K. To clarify the present metal–insulator change, we carried out the magnetization and magnetoresistance measurements in magnetic fields up to 50 T. The magentization at 4.2 K saturates above 40 T, reaching 1.75 µB/U at 50 T for the magnetic field along the magentic easy-axis, namely the [001] direction. The corresponding electrical resistivity at 4.2 K is steeply reduced in magnitude from 1 ×103Ω·cm to 2 ×10-2Ω·cm at 50 T only when the magnetic field is applied along the [001] direction. The temperature dependence of the electrical resistivity at 50 T indicates a usual metallic behaviour. The conduction electrons are most likely released from the trapped U-sites when the 5f-CEF magnetic moments are fully polarized in high magnetic field of 50 T. The present experimental results are discussed from the viewpoint of the magnetic polaron.