Specific heat of the Ce(Cu1−xNix)4Ga alloys

The influence of the modification of the 3d electronic states in the heavy fermion compound CeCu4Ga by substitution of Cu by Ni is reported. It has been verified that the crystallographic structure is hexagonal of the CaCu5 type and is preserved for all the x values in the alloys Ce(Cu1−xNix)4Ga. The measurements of the specific heat Cp(T) have revealed that the huge electronic specific coefficient γ = 3.3 J mol−1 K−2 for CeCu4Ga is reduced with the progressive Ni addition and follows the behavior of the hybridization parameter of the Ce f states with the conduction electrons. The analysis of the specific heat of the non-magnetic reference compound LaCu4Ga has shown that including the mass correction corresponding to the change of Ce by La and Cu by Ni does not provide a correct estimation of the phonon term in the Ce(Cu1−xNix)4Ga alloys.