ANISOTROPIC SPECIFIC-HEAT OF CECU6 IN MAGNETIC-FIELDS

The specific heat of a single crystalline CeCu//6 was measured at low temperatures down to 0. 15 K in magnetic fields up to 6 T. The ratio of the specific heat to temperature, C/T, showed anomalously large values at low temperatures, indicating the heavy Fermi-liquid nature of a Kondo-lattice ground state. The magnetic fields suppressed C/T at low temperatures. Varying the field directions with respect to the crystallographic axes, an anisotropy in C/T was found, which is consistent with the results of the magnetic susceptibility and the magnetoresistance at low temperatures. The observed behavior of C/T is interpreted by a simple model with Lorentzian density of states at the Fermi level.