Dielectric and magnetic response of Sr-Zn ferrite composite

Sr-Zn ferrite composites were synthesized by chemical coprecipitation with different sintering process. The composites were characterized by XRD, XPS, IR, VSM, and N-2-adsorption. The results revealed that the composites were composed of S-type ZnFe2O4 and M-type SrFe12O19. Zn2+ ions inserted and occupied the 12k or 2a sites for Fe3+ ions in M-type SrFe12O19. The Zn2+ ions were therefore not on the external surface of the composites. The microwave absorption properties at a frequency range of 0-18 GHz were estimated using the electromagnetic parameters obtained through the agency of microwave vector network analyzer. The microwave absorbing properties of composites were excellently superior to that of the pure SrFe12O19 or ZnFe2O4 due mainly to the exchange coupling between the hard- and soft-magnetic phases. The synthesis process was found to facilitate mass production for various composite materials, especially the two phases or multiphase composite materials.