TRANSPORT-PROPERTIES OF THE KONDO-LATTICE MODEL IN THE LIMIT S=INFINITY AND D=INFINITY

The Kondo lattice model with Hund's ferromagnetic spin coupling is investigated as a microscopic model of the perovskite-type 3d transitionmetal oxide La1-xSrxMnO3. In the classical spin limit S = infinity and the infinite-dimensional limit D = infinity, the one-body Green's function is exactly calculated. Transport properties of the system in the presence of magnetic fields are obtained. The giant magnetoresistance of this model, which is in good agreement with the experimental data of La1-xSrxMnO3, is explained by the spin-disorder scattering process.