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arXiv 0811.4011cond-mat.str-elcond-mat.supr-con
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压力下URu2Si2的电阻率和热膨胀测量

Electrical Resistivity and Thermal Expansion Measurements of URu2Si2 under Pressure

Gaku Motoyama, Nobuyuki Yokoyama, Akihiko Sumiyama, Yasukage Oda

摘要:

我们进行了同时测量的电阻率和热膨胀的重费米子化合物URu 2Si 2在压力下使用一个单晶。我们观察到一个相变异常之间的隐藏(HO)和反铁磁(AFM)有序状态在TM在两个测量的温度依赖性。对于电阻率,TM处的异常与顺磁状态(PM)和HO之间的相变温度T0处的明显驼峰异常相比非常小,并且对于I//a轴和c轴分别仅表现出轻微的增加和减少。我们估计每个激发间隙的HO,Delta_HO,和AFM,Delta_AFM,从电阻率的温度依赖性; Delta_HO和Delta_AFM具有不同的压力依赖性彼此。另一方面,热膨胀的温度依赖性在T0处表现出小的异常,在TM处表现出大的异常。T0和TM相边界的压力依赖性表明,不存在临界终点,两相边界在临界点相交。

英文摘要:

We carried out simultaneous measurements of electrical resistivity and thermal expansion of the heavy-fermion compound URu2Si2 under pressure using a single crystal. We observed a phase transition anomaly between hidden (HO) and antiferromagnetic (AFM) ordered states at TM in the temperature dependence of both measurements. For the electrical resistivity, the anomaly at TM was very small compared with the distinct hump anomaly at the phase transition temperature T0 between the paramagnetic state (PM) and HO, and exhibited only a slight increase and decrease for the I // a-axis and c-axis, respectively. We estimated each excitation gap of HO, Delta_HO, and AFM, Delta_AFM, from the temperature dependence of electrical resistivity; Delta_HO and Delta_AFM have different pressure dependences from each other. On the other hand, the temperature dependence of thermal expansion exhibited a small anomaly at T0 and a large anomaly at TM. The pressure dependence of the phase boundaries of T0 and TM indicates that there is no critical end point and the two phase boundaries meet at the critical point.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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