Abstract
A series of W-type hexagonal ferrites with the composition BaZn2-xMgxFe16O27 (where x = 0.0, 0.4, 0.8, 1.2, and 1.6) were prepared by the ceramic technique, to investigate their DC and AC electric conductivity, thermoelectric power, and their parameters as a function of composition and temperature. The DC conductivity exhibited a semiconducting behavior and its values decreased with increase of the Mg ions due to the migration of iron ions from the octahedral to tetrahedral sites. The thermoelectric power showed that the majority carriers are electrons whose mobility are thermally activated. Many conduction mechanisms are discussed to explain the transport properties for these ferrites. It was found that the multiple hopping conduction mechanism is the predominant mechanism. (C) 2003 Published by Elsevier B.V.