LAUSR

Abstract Magnesium and titanium co-substituted M-type barium calcium hexaferrites Ba0.5Ca0.5Fe12-2xMgxTixO19 (0.0 ≤ x ≤ 0.5) have been synthesized by a solid state reaction method and characterized by XRD, XPS, FTIR, SEM, SQUID. XRD patterns confirm single phase M-type hexaferrite and various parameters such as lattice constants, cell volume, average grain size, X-ray density and profile parameters have been calculated from XRD data. XPS survey and FTIR spectra confirm that hexagonal crystal structure is completely formed, which are correlate closely with the results of Reitveld refined XRD patterns. SEM images of the magnetic powders confirm the hexagonal platelet-like shape. The apparent irreversibility between the zero-field-cooling (ZFC) and field-cooling (FC) curves is observed below 390 K, and the ZFC magnetization curves display a broad peak at a temperature TM. The results are discussed within the framework of random particle assembly model and associated with the magnetic domain wall motion. The saturation magnetization Ms slightly increases with increasing x up to 0.2 at 300 K, and then decreases for x > 0.2. The first anisotropy constant (K1), magnetic anisotropy field (Ha) and coercivity (Hc) decrease with increasing x. These results are discussed in light of the cationic distributions based on the results of the structural refinements.