Transport Properties of Heavy Fermion Compounds
Transport Properties of Heavy Fermion Compounds
复制标题
重费米子化合物的输运性质
DOI：
10.4131/jshpreview.7.412
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Heribert Wilhelm
中科院分区：
文献类型：
--
作者：
D. Jaccard;E. Vargoz;K. Alami;Heribert Wilhelm
本文介绍了一种在压力达30 GPa、温度达25 mK、磁场达10 T的条件下测量电阻率和绝对热电势的方法。以CeCu_2Ge_2和CeCu_2Si_2为例，重点讨论了正常相和超导性质之间的相互作用。随着压力的增加，CeCu_2Ge_2的行为从反铁磁有序的Kondo系统演变为中间价化合物的特征，Kondo温度增加约两个数量级。在8-10 < P < 20 GPa的压力窗口中，出现了超导相，在低压下与磁有序相竞争。对于CeCu_2Si_2，用费米液体定律的系数和上临界场的初始斜率来确定载流子的有效质量。磁不稳定性的研究显着CeRu 2Ge 2和Yb基化合物的压力诱导磁有序倾向于发展。最后，与传统观点相反，我们认为，在重费米子的剩余电阻率的很大一部分是最有可能不独立的温度，暂时归因于近藤孔，它可以是非常压力以及样品依赖。[电阻率、热电势、重费米子、磁序、超导性]
A technique for measuring the electrical resistivity and absolute thermopower is presented for pressures up to 30 GPa, temperatures down to 25 mK and magnetic fields up to 10 T. With the examples of CeCu2Ge2 and CeCu2Si2 we focus on the interplay of normal phase and superconducting properties. With increasing pres- sure, the behaviour of CeCu2Ge2 evolves from that of an antiferromagnetically ordered Kondo system to that characteristic of an intermediate valence compound as the Kondo temperature increases by about two orders of magnitude. In the pressure window 8-10 < P < 20 GPa, a superconducting phase occurs which com- petes at low pressure with magnetic ordering. For CeCu2Si2 the effective mass of carriers is probed by both the coefficient of the Fermi liquid law and the ini- tial slope of the upper critical field. The magnetic instability is studied no- tably for CeRu2Ge2 and Yb-based compounds for which pressure-induced magnetic ordering tends to develop. Finally, contrary to conventional wisdom, we argue that in heavy fermions a large part of the residual resistivity is most likely not independent of temperature; tentatively ascribed to Kondo hole, it can be very pressure as well as sample dependent. [electrical resistivity, thermoelectric power, heavy fermion, magnetic order, superconductivity]