Hysteresis analysis of Co-Ti substituted M-type Ba-Sr hexagonal ferrite

The magnetic, crystallographic properties and grain morphology of synthesized Ba0.5Sr0.5CoxTixFe(12 - O-2x)(19) ferrite have been investigated by XRD, SEM and VSM. XRD and SEM confirm M-type hexagonal crystal structure. X-ray diffraction indicates expansion of hexagonal unit cell with substitution of Co2+ and Ti4+ ions. The microstructure governs increase in density and intergrain connectivity with substitution. The preferential site occupancy of substituted Co2+ and Ti4+ ions results in rapid decline of anisotropy field, hysteresis loops also revealed same effect of substitution. Coercivity and remanence magnetization can be easily controlled by varying substitution while maintaining high saturation magnetization, making it useful for recording media. (C) 2009 Elsevier B.V. All rights reserved.