Electrical transport properties of zinc-substituted cobalt ferrites

Electrical conductivity (sigma) and thermoelectric power (s) studies of zin c-substituted cobalt ferrites are undertaken as a function of composition a nd temperature. On the basis of the Seebeck coefficient (S), the ferrites u nder investigation have been classified as n-type and p-type semiconductors . Electrical conductivity of all the ferrites is found to increase with inc reasing temperature with a change of the slope at magnetic transition (T-c) . The activation energy in the ferrimagnetic region is in general less than that in paramagnetic region. The values of charge carrier concentration an d mobility are also computed and discussed as a function of composition and temperature. An attempt is made to explain the conduction mechanism in the se ferrites. (C) 1999 Elsevier Science B.V. All rights reserved.