Microstructural and Magnetic Properties of Ti<sup>2+</sup>-Mn<sup>4+</sup> Substituted Barium Hexaferrite

Abstract

In this paper we report the microstructure and magnetic properties of Ti 4+ -Mn 4+ ions substitued barium hexaferrites (BHF) with formula of BaFe 12-2x Mn x Ti x O 19 ( x = 0.2, 0.4, 0.6 and 0.8) which prepared by mechanical alloying and successive sintering at 1100 °C. Ti 4+ -Mn 4+ ions were obtained from TiO 2 and MnO precursors which were mechanically alloyed together with BaCO 3 and Fe 2 O 3 precursors. X-ray diffraction patterns for sintered samples confirmed that the materials are consisted with single phase BHF structure. Unit cell volume and crystallite size was found increase with increasing x . The crystallite size for all samples was below 70 nm, but microstructure observation shown that the particle size is in range of 200 - 400 nm, which concluded that the grains are polycrystalline. The saturation magnetization is increases up to x = 0.4 and decrease for higher x values, while the coercivity remain decreases monotonically. These results were interpreted in terms of the site preferential occupation of Ti 2+ and Mn 4+ at low level substitution.