Study of the ultra-low temperature resistances of heavy fermion system CeCu6-xNix

CeCu6 is one of heavy fermion materials. The effect of the partly substitut ion of Cu by Au, Ag, Id and PL on the low temperature properties has been i ntensively studied. In this paper, we study the temperature dependence of r esistance of CeCu6-xNix(x = 0.00, 0.05, 0.10, 0.15, 0.20) at temperatures b elow 1K. Experimental result shows that the temperature dependence of resis tance changes with increase of doping content x. Below 500mK, the resistanc e 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 th is system. In the case of Au substitution of Cu, the critical doping of whi ch 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 expan sion. But in the present case, the ground state of Ni doping systems change s from FL to NFL due to the magnetism of Ni.