Theory of the resistivity of heavy-fermion compounds

The resistivity of the Anderson lattice is calculated as a model for heavy-fermion compounds in a semi-phenomenological theory. In this theory, the resistivity is expressed by the dynamical susceptibility which describes spin fluctuations and can be measured by means of neutron scattering. The Kondo effect is taken into account for a single f-electron spin which is coupled to all other spins and to the conduction electrons. This approach neglects multiple intersite-scattering of the conduction electrons and leads to an expression in which the Kondo resistivity of independent spins is multiplied by a factor which describes the spin dynamics. Here, the influence of the spin interactions on the Kondo effect has been taken into account in the simplest approximation only. At high temperatures this factor leads only to a small modification of the Kondo effect but at low temperatures for the Anderson- or Kondo-lattice it leads to a T exp 2 -law in the resistivity which scales with the Kondo temperature T sub K . Deviations from this T exp 2 -law are predicted at temperatures of the order T = 0.2 T sub K for Ce compounds. 66 ref.--AA