Ferromagnetic polarons in the Kondo lattice model

Using a bosonization technique we describe the ferromagnetic polaron format ion in one-dimensional Kondo lattice models with partial conduction band fi lling. We show that at low electron concentration large ferromagnetic polar ons are formed. The width of these polarons will gradually decrease as the electron concentration increases and finally local Kondo singlets will domi nate. Bipolarons or multipolarons will not form in the lattice.