Electrical transport properties of some substituted nickel ferrites

Thermopower and electrical conductivity studies of some substituted nickel ferrites are undertaken as a function of composition and temperature. On the basis of the sign of the Seebeck coefficient S, the ferrites under investigation have been classified as n-type semiconductors. All the ferrites are found to exhibit clear and well-defined transitions near the Curie temperature in both the Seebeck coefficient and the electrical conductivity vs. temperature plots. Activation energies of all the samples are calculated. An attempt is made to explain the conduction mechanism in these samples.