Thermoelectric power and electrical conductivity of Cu-Ti ferrite

The electrical conductivity and thermoelectric power were measured in the range of temperature from 300 to 773 K for the mixed Cu-Ti ferrite Cu1-xTixFe2O4 with x=0 to 0.5. It was found that all compositions behave as n-type semiconductors in the measured range of temperatures. The conduction mechanism was discussed on the basis of a small-polaron hopping model. The activation energy from the conductivity data E-sigma was found to be higher than that calculated from the thermoelectric power E-s. The discrepancy between E-sigma and E-s is evidence for the existence of thermally activated hopping in the ferrite system. (C) 1999 Elsevier Science B.V. All rights reserved.