Thermoelectric effect in La0.6Pb0.4Mn1−xCoxO3

The thermopower (S) for La0.6Pb0.4Mn1−xCoxO3 (x=0,0.025,0.05) has been measured. The change of sign in S is found to be associated with difference in band filling, while change of “transport heat capacity” Ce* around Tc for three samples reflects the nature of carriers as well as electron scattering caused by spin fluctuation and spin disorder. The calculated “transport entropy” ξ* reflects the spin scattering interaction between itinerant electrons and localized electrons.