The effect of SiO2 addition on structural, magnetic and electrical properties of strontium hexa-ferrites

Sr-hexaferrites with the addition of SiO2 (0-2.0 wt%) have been prepared by the solid-state reaction method. The structural characterization of the samples confirmed the major phase of Sr-hexa-ferrite. The average grain size was found within the range of micron. The coercivity increased up to 1.5 wt% of silica addition and then decreased. Remanence has decreasing trend with the increase of silica percentage. The DC electrical properties were studied as a function of temperature. Activation energy and drift mobility were determined. The room temperature electrical resistivity increased from 5.95 x 10(8) to 1.76 x 10(9) (Omega-cm), which in turn increased the activation energy with the successive addition of SiO2. The dielectric properties as a function of frequency, under normal conditions, were also measured. From 80 Hz to 1 MHz the dielectric constants and loss factors remained within the range of 3340-12 and 5.75-0.21, respectively. (c) 2006 Elsevier B.V. All rights reserved.