Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland.
J Phys Condens Matter. 2010 Apr 28;22(16):165601. doi: 10.1088/0953-8984/22/16/165601. Epub 2010 Mar 30.
CeNiSn is known as a semimetallic system with a small pseudogap at the Fermi energy. We investigate the effect of Rh doping on the Kondo insulator CeNiSn by means of measurements of ac magnetic susceptibility and specific heat. We show that the formation of the Kondo insulator narrow gap in CeNi(1 - x)Rh(x)Sn is associated with disorder-induced f-electron localization. For doped CeNiSn with x ≤ 0.06, the electrical resistivity data follow an activation and variable range hopping behaviour at low T, consistent with weak disorder and localization, while C/T is large, which is not a common feature of Kondo insulators. For x > 0.06, the system is metallic and exhibits non-Fermi liquid behaviour with magnetic susceptibility χ ∼ T( - n) with n ∼ 0.4 and electrical resistivity ρ ∼ T.
CeNiSn 被认为是一种具有费米能级附近小赝能隙的半金属体系。我们通过交流磁化率和比热的测量研究了 Rh 掺杂对 Kondo 绝缘体 CeNiSn 的影响。结果表明，CeNi(1 - x)Rh(x)Sn 中 Kondo 绝缘体窄能隙的形成与无序诱导的 f 电子局域化有关。对于掺杂的 CeNiSn（x ≤ 0.06），在低温下，电导率数据遵循激活和变程跳跃行为，这与弱无序和局域化一致，而 C/T 较大，这不是 Kondo 绝缘体的常见特征。对于 x > 0.06，系统是金属的，并表现出非费米液体行为，磁化率 χ∼T(-n)，其中 n∼0.4，电导率 ρ∼T。
