CHARGE TRANSPORT AND CONDUCTION MECHANISM OF COPPER SUBSTITUTED MAGNESIUM ALUMINIUM FERRITES

Abstract

Electrical conductivity (σ) and thermopower (S) studies of polycrystalline copper substituted magnesium aluminium ferrites of different composition were investigated in the temperature range 300–800 K. Plots of log (σT) versus 10 3 /T are almost linear and show a clear transition near the Curie temperature. On the basis of the sign of Seebeck coefficient, all the samples under investigation have been classified as n-type semiconductors. The temperature variation of Seebeck coefficient curves also exhibited a well defined magnetic transition at the Curie temperature. Using the temperature variation of charge carrier mobility a conduction mechanism in these ferrites is suggested.