Abstract
Electrical properties as a function of composition, frequency and temperature for a series of W-type hexagonal ferrites with the general formula BaCoZn1-xMgxFe16O27; 0 <= x <= 0.6prepared using the conventional ceramic method were studied. These samples are semiconductor-like materials, where the ac conductivity increases with increasing temperature. The results show that the conduction mechanism depends on the Mg2+ substitution. The transition temperature(T-sigma) increases with increasing Mg content and gives a humpat x=0.5; after that T-sigma decreases again. Both the ac conductivity and dielectric constant vary with Mg content and reach the highest value at x=0.5, due to the highest value of the ratio of Fe2+/Fe3+ at x=0.5. The peak value of the dielectric constant depends on the Mg content x. Crown Copyright (C) 2009 Published by ElsevierB.V. All rights reserved.