Correlation of magnetoresistance and thermoelectric power in valence-doped La0.7Ca0.3Mn1- xFexO3-d compounds.

The temperature dependences of the thermoelectric power, TEP, (S) and magnetoresistance (MR) effect of La1-xLixMnOy (x = 0.05, 0.1, 0.15, 0.2 & 0.25 at %) fixed valence doped compounds were studied between 80K and 320K. X-ray powder diffraction (XRD) showed that the samples are single phase. We found the correlation of structures to the mag-netoresistance (MR) and the thermoelectric power (S) which we assigned to change the specific branches of the magnon /phonon spectra with x. We also observed a splitting of the Curie and the metal insulating temperature TC > Tms.