Structural and magnetic study of the Ti4+-doped barium hexaferrite ceramic samples: Theoretical and experimental results

We present a theoretical and experimental study of the structural and magnetic properties of M-type Ti4+-doped barium hexaferrite BaFe(12-(4/3)x)TixO19 with x=0, 0.1, 0.2, 0.3, 0.5, 0.7 and 1.3. The XRD patterns and magnetic measurements show appreciable variations in the values of the saturation magnetization and the magnetic anisotropy field, H-an, with increasing Ti4+ content. We did not observe significant changes in the Lotgering factor along the (001) direction and in the texture coefficient, C-ex, which was estimated from the torque curves. The magnetic properties of these materials are explained by the combined effect of the coherent rotation of the magnetic domains and the replacements of Fe3+ by Ti4+ ions in the octahedral and tetrahedral sites. The influence of the Ti4+ content on the samples was studied theoretically by using a statistical phenomenological model. The main purpose of the model is to make preliminary predictions of the distribution of any dopant cation in the Fe3+ sites. As a result, we are able to analyze both structural and magnetic features of M-type barium hexaferrite. (C) 2011 Elsevier B.V. All rights reserved.