重费密子系统CeCu_(6-x)Ni_x的极低温电阻研究  

STUDY OF THE ULTRA-LOW TEMPERATURE RESISTANCES OF HEAVY FERMION SYSTEM CeCu_(6-x)Ni_x

作　　者：孟继宝[1] 陈兆甲[1] 雒建林[1] 白海洋[1] 汪卫华[1] 郑萍[1] 张杰[2] 苏少奎[1] 王玉鹏[1] 

机构地区：[1]中国科学院物理研究所极端条件物理开放实验室,北京100080 [2]重庆大学应用物理系,重庆400044

出　　处：《物理学报》2001年第8期1632-1636,共5页Acta Physica Sinica

基　　金：国家自然科学基金 (批准号 :197340 0 1)资助的课题&&

摘　　要：CeCu6 是一种重费密子系统 ,采用Ni替代Cu研究磁性原子掺杂的多晶样品CeCu6 -xNix(x =0 .0 0 ,0 .0 5 ,0 .10 ,0 .15 ,0 .2 0 )在极低温下的电阻随温度的变化规律 .实验结果表明 ,随着Ni原子掺杂量的增加 ,电阻的规律发生变化 .在 5 0 0mK以下 ,x≈ 0 .1的样品电阻与温度呈线性关系 ,表现出非费密液体行为 ,而其他样品皆为典型的费密液体 ,x≈ 0 .1是其临界掺杂成分 .对比用Au替代的情况 ,临界掺杂成分也是 0 .1,但Au掺杂是靠体积膨胀来改变合金的基态性质 。CeCu6 is one of heavy fermion materials. The effect of the partly substitution of Cu by Au, Ag, Id and PL on the low temperature properties has been intensively studied. In this paper, we study the temperature dependence of resistance of CeCu6-xNix(x = 0.00, 0.05, 0.10, 0.15, 0.20) at temperatures below 1K. Experimental result shows that the temperature dependence of resistance changes with increase of doping content x. Below 500mK, the resistance of sample with x approximate to 0.1 has a linear temperature dependence, showing a typical non-Fermi liquid behavior, while other samples behave as Fermi liquid. This means x approximate to 0.1 is the critical doping for this system. In the case of Au substitution of Cu, the critical doping of which is also x = 0.1, the ground state of the system is changed from Fern-ii-liquid to non-fern-ti liquid and antiferromagnetic ordering by volume expansion. But in the present case, the ground state of Ni doping systems changes from FL to NFL due to the magnetism of Ni.

关 键 词：重费密子系统 临界掺杂 非费密液体 极低温 电阻 

分 类 号：O513[理学—低温物理]