Structural and magnetic properties of SrFe12-2xTixRuxO19

The magnetic properties of M-type Strontium hexaferrites can be modified by partially substituting Fe ions by other metallic ions. In this work, we report on the effect of the substitution of Ti2+ and Ru4+ ions for Fe3+ ions on the magnetic properties of the system, and the dependence of these properties on the cationic distribution in the lattice. SrFe12-2xTixRuxO19 hexaferrite samples were prepared by ball milling and sintering at 1100 degrees C the appropriate amounts of the starting powders. The structural and magnetic properties of the fabricated samples were investigated using X-ray diffraction, SEM, Mssbauer spectroscopy, and vibrating sample magnetometry. It was found that Ti-Ru substitution improved the crystallinity of the prepared samples slightly, and did not influence the particle size appreciably. Mssbauer spectroscopy revealed that Ti2+ and Ru4+ ions substituted Fe3+ ions at the 4f(2), (4f(1) + 2a) and 2b sites for x values up to 0.2, and at the 12k site for x > 0.2. The saturation magnetization increased up to x = 0.2, and then decreased for higher x values, while the coercivity decreased monotonically, recording a reduction of 70% at x = 0.3. The magnetic properties of the system were interpreted in terms of the distribution of Ti2+ and Ru4+ ions in the hexagonal lattice. (C) 2012 Elsevier B.V. All rights reserved.