Precize measurements of the transport propenties of f-electron ststem at low temperatures

低温下f电子体系输运特性的精确测量

基本信息

批准号：
09640442
负责人：
SATO Hideyuki
金额：
$ 2.3万
依托单位：
TOKYO METROPOLITAN UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

项目摘要

The Hall coefficient (R_H) and thermoelectric power (S) have been systematically investigated on f-electron compounds down to the He^3 temperature region. The lower temperature measurements using a dilution refrigerator have been also proceeded. Special emphasis were put on the materials exhibiting non-Fermi liquid anomalies which have been the systems of current interest in the field of f-electrons. In order to obtain reliable results, we have started from the high quality crystal growth for each system. For comparison with R_H and S, we also measured the resistivity (P), specific heat, and magnetic susceptibility.Y_<0.8>U_<0.2>Pd_3 : R_H shows a linear increase with decreasing temperature, which is slight1y strange as an ordinary magnetic systems. It can be understood, however, as due to the anomalous Hall effect, if we take into account the closeness of the concentration to the 0 K-spinglass transition.CeNi_2Ge_2 : R_H at high temperatures could be explained as due to the ordinary skew scattering, while R_H at low temperatures does not follow the relation, R_H * P^2, predicted from the Fermi liquid (FL) theory. It rather follows R_H * ln(p) in a wide temperature range. At this stage, however, we cannot conclude that the deviation from the FL prediction in R_H is directly related with the non-FL behaviors in the other properties.Y_<1-x>U_xRu_2Si_2, Th_<1-x>U_xRu_2Si_2 : These systems were the most probable candidates exhibiting anomalies originating from the two channel Kondo effect. Anomalous behaviors appear below a characteristic temperature (T_c). R_H was also found to exhibit an anomalous decrease below T_c, which is hardly explainable within the ordinary anomalous Hall effect. We also found S sharply decreases below T_c and shows a deep minimum at lower temperatures.CeFe_2Ge_2 : We found CeFe_2Ge_2 to be a new heavy Fermion metamagnet which shows anomalous transport properties, suggesting the non-FL behavior related with the spin fluctuation.

HALL系数（R_H）和热电功率（S）已系统地研究了F-电子化合物至He^3温度区域。还进行了使用稀释冰箱的较低温度测量。特别重点放在表现出非Fermi液体异常的材料上，这些材料一直是F-Electron领域中目前感兴趣的系统。为了获得可靠的结果，我们已经从每个系统的高质量晶体生长开始。为了与R_H和S进行比较，我们还测量了电阻率（P），比热和磁敏感性。但是，这可以理解，因为我们要考虑到集中注意力与0 k-spinglass跃迁的亲密关系。Ceni_2ge_2：r_h在高温下可以解释为普通的偏斜散射，而低温下的R_H，而R_H在较低的温度下并不能遵循R_H * p^p^p^p^p^p^p^p^p^2，fly file（fl）的理论（fl）。相反，它遵循R_H * LN（P）在较宽的温度范围内。但是，在这个阶段，我们无法得出结论，与R_H中的FL预测的偏差与其他属性中的非FL行为直接相关。Y__<1-x> u_xru_2si_2，th_ <1-x> u_xru_2si_2：这些系统是表现出最有可能的候选者，表现出了两个通道kondo kondo kondo seard kondo kondo searto kondo的效果。异常行为出现在特征温度（T_C）下方。还发现R_H在T_C以下表现出异常降低，这在普通异常的大厅效应中几乎无法解释。我们还发现S急剧下降到T_C以下，并在较低的温度下显示最低最低。CEFE_2GE_2：我们发现CEFE_2GE_2是一种新的重型费米子元磁体，显示出异常的运输特性，表明与自旋波动有关的非FL行为。