Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Wrocław, Poland.
Phys Rev Lett. 2012 Feb 10;108(6):066405. doi: 10.1103/PhysRevLett.108.066405.
Thermodynamic and transport properties of the La-diluted Kondo lattice CeNi(2)Ge(2) were studied in a wide temperature range. The Ce-rich alloys Ce(1-x)La(x)Ni(2)Ge(2) were found to exhibit distinct features of the coherent heavy Fermi liquid. At intermediate compositions (0.7≤x≤0.9), non-Fermi liquid properties have been observed, followed by the local Fermi liquid behavior in the dilute limit. The 4f-electron contribution to the specific heat was found to follow the predictions of the Kondo-impurity model in both the local as well as the coherent regimes, with the characteristic Kondo temperature decreasing rapidly from about 30 K for the parent compound CeNi(2)Ge(2) to about 1 K in the most dilute samples. The specific heat does not show any evidence for the emergence of a new characteristic energy scale related to the formation of the coherent Kondo lattice.
在很宽的温度范围内研究了 La 稀释的 Kondo 格子 CeNi(2)Ge(2)的热力学和输运性质。富 Ce 的合金 Ce(1-x)La(x)Ni(2)Ge(2)表现出相干重费米液体的明显特征。在中间成分(0.7≤x≤0.9)下,观察到非费米液体性质,然后在稀释极限下表现出局部费米液体行为。比热中的 4f 电子贡献符合 Kondo 杂质模型的预测,无论是在局部还是相干区域,特征 Kondo 温度都从母体化合物 CeNi(2)Ge(2)的约 30 K 迅速降低到最稀释样品中的约 1 K。比热没有显示出与相干 Kondo 格子形成相关的新特征能量尺度出现的任何证据。