Thermal expansion of monocrystalline heavy-fermionCeCu6

Thermal-expansion measurements on monocrystalline ${\mathrm{CeCu}}_6$ in the temperature range 1.5<T<100 K are presented. The coefficient of linear thermal expansion is strongly anisotropic. The volume expansion exhibits a maximum at 2.5 K that is attributed to the Kondo-lattice effect. The data are compared with specific-heat data (T<20 K) on the same sample. An analysis in terms of Grüneisen parameters yields the large value ${\Gamma }_{\mathrm{el}=57\mathrm{}}$ for the heavy-fermion contribution.