Preparation and characterization of microwave absorption ferrite coatings

M-type hexaferrite SrFe9Mn1.5Ti1.5O19 and BaFe9Mn1.5Ti1.5O19 were synthesized by usual ceramic sintering method. The powders of the 70% ferrites by weight were mixed with resin epoxy. The prepared composite was sprayed on a 1.8mm-thick aluminum 5083 substrate. Their structure and microwave adsorption property were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM), and vector network analyzer. The results showed that the magnetoplumbite structure for both samples was formed and powders had the hexagonal or amorphous morphology with particle sizes within the range of 1-5µm. The maximum reflection loss for Sr-ferrite coating was 18.84 GHz equal to (-26.43 dB). The waveband of absorption was approximately 3GHz more than 15dB for reflection losses. The results for Ba-ferrite were 19.18 GHz with (-44.11dB) reflection loss and 3.2 GHz waveband. Both coatings can be good candidates for stealth radar targets.