Effect of Mn-Co and Co-Ti substituted ions on doped strontium ferrites microwave absorption

M-type strontium hexaferrite SrFe9Mn1.5Co1.5O19 and SrFe9Co1.5Ti1.5O19 were synthesized by solid-state method. X-ray diffraction (XRD), scanning electron microscopy (SEM), and susceptometer were used for characterization of obtained powders. The ferrite-polymer composites with different ferrite ratios of 50%, 60%, 70% and 80% in polyvinylchloride matrix were prepared. The microwave absorption properties of these composites were investigated in 12-20 GHz frequency range. The results showed that the particle size of the two samples had a wide range of distribution and the magnetoplumbite structure was formed in the samples. The composites of both ferrite compositions with 70% ferrite content have shown higher losses compared to composites with other ratios. It was concluded that the prepared composites could be good candidates for electromagnetic compatibility and other practical applications at high frequencies. (C) 2008 Elsevier B.V. All rights reserved.