Effect of sintering temperature on electrical conductivity of mixed lithium-cadmium ferrites

The electrical conductivity (sigma) of mixed lithium-cadmium ferrites havin g the compositional formula Li0.5-x/2CdxFe2.5-x/2O4 (where x = 0.2, 0.4, 06 , 0.8 and 1.0) sintered at 1200, 1250 and 1300 degrees C have been investig ated from room temperature to well beyond the Curie temperature by two prob e method. The porosity and activation energy were calculated. It was found that the electrical conductivity is progressively increasing with the incre ase of sintering temperature while porosity and activation energy decrease continuously. Plots log (sigma T) vs. 10(3)/T are almost linear and shown a transition near the Curie temperature except in the case of cadmium ferrit e. The conduction mechanism in these ferrites can be explained on the basis of hopping mechanism. (C) 1999 Elsevier Science B.V. All rights reserved.