Thermoelectric power of potassium doped lanthanum manganites at low temperatures

The temperature-dependent resistivity and thermoelectric power of monovalent (K) doped La1−xKxMnO3 polycrystalline pellets (x=0.05, 0.10 and 0.15) between 50 and 300 K are reported. K substitution enhances the conductivity of this system. Curie temperature (TC) also increases from 260 to 309 K with increasing K content. In the paramagnetic region (T>TC), the electrical resistivity is well represented by adiabatic polaron hopping, while in the ferromagnetic region (TTC whereas at low temperatures (T