Influence of sintering time on structural, magnetic and electrical properties of Si-Ca added Sr-hexa ferrites

Sr-hexa ferrites with the addition of Si (0.5 wt%) and Ca (0.5 wt%) have been prepared by solid-state reaction method with sintering time variation ranging from 2 to 10 h. The structural characterization of the samples confirmed the major phase of Sr-hexa ferrite. Average grain size was found within the range of 1-4 mu m. Vicker hardness increased from 512 to 1187H(v). The coercivity and remanence had the ranges from 596 to 4255 Oe and 324 to 516 G, respectively. The DC electrical resistivity measurements were carried out by two-probe method as a function of temperature from 303 to 723 K. The room temperature DC resistivity increased from 1.67 x 10(6) to 2.89 x 10(8) Omega cm in turn the activation energy also increased from 0.314 to 0.495 eV. The DC electrical resistivity decreased while drift mobility increased with the rise in temperature, ensuring the semi-conducting behavior. Dielectric properties were studied as a function of frequency in the range of 80 Hz to 1 MHz at room temperature. (c) 2007 Elsevier B.V. All rights reserved.