Thermoelectric power of compounds with cerium: Influence of the crystalline field on the Kondo effect

The influence of the crystalline field on the Kondo effect of compounds with cerium is studied in the framework of an effective Hamiltonian which describes the resonant scattering character of cerium and which takes into account combined spin and orbit exchange scattering. The third-order perturbation-theory thermoelectric power is computed exactly in the case of two levels split by the crystalline field. The model is applied to the thermoelectric-power measurements of ${\mathrm{Ce}}_{1-x}{\mathrm{La}}_x{\mathrm{Al}}_3$ and the agreement with experiment is good, especially for low cerium concentration.