Conduction mechanism of BaCo2-xNixFe16O27

A series of W-type hexaferrite samples of BaCo2-xNixFe16O27 with (x = 0.0, 0.4, 0.8, 1.2, 1.6) were prepared by using the well known ceramic technique to investigate their electrical properties. The results of thermoelectric power coefficient and DC electrical conductivity suggested that the conduction mechanism in this system is due to hopping of electrons between Fe2+ and Fe3+ along with the hole transfer between Ni2+ and Ni3+. It was found that the conductivity increases as the replacement of Co2+ ion by Ni2+ ion increases. The results of real AC conductivity shows a dispersion with frequency. The dispersion decreases as the temperature increases. The dispersion of AC conductivity was explained on the basis of Koops model. (C) 1999 Elsevier Science B.V. All rights reserved.