Crystal-field excitations in the heavy-fermion alloys CeCu6−x Au x studied by specific heat and inelastic neutron scattering

The specific heat of CeCu_6–x Au _x withx=0,0.3, and 0.9, and of the corresponding La homologues has been measured between 1.5 K and 150 K. With increasingx we find progressively better-defined Schottky anomalies arising from the crystal-field splitting, which is attributed to the decrease of the Kondo temperature. Both observations are in line with the results of inelastic neutron-scattering data performed on samples withx=0.5. Overall, the crystal-field splitting does not change very much upon alloying with Au. A detailed analysis shows that forx=0.5 the quasielastic line width is smaller and the inelastic crystal-field transitions are better resolved compared to CeCu₆.