Magnetic and microwave absorption properties of BaFe12−x (Mn0.5Cu0.5Zr)x/2O19 synthesized by sol–gel processing

BaFe12−x (Mn0.5Cu0.5Zr)x/2O19 hexaferrites with x=1, 2 and 3 were prepared by sol–gel process. The ferrite powders possess hexagonal shape and are well separated from one another. The powders of these ferrites were mixed with polyvinylchloride (PVC) plasticizer to be converted into a microwave absorbing composite ferrite with a thickness of 1.8 mm. X-ray diffractometer (XRD), scanning electron microscope (SEM), ac susceptometer, vibrating sample magnetometer and vector network analyzer were used to analyze its structure, electromagnetic and microwave absorption properties. The results showed that magnetoplumbite structures for all samples were formed. The sample with higher magnetic susceptibility and coercivity exhibits a larger microwave absorbing ability. Also the present investigation demonstrates that a microwave absorber using BaFe12−x(Mn0.5Cu0.5Zr)x/2O19 (x=2 and 3)/PVC with a matching thickness of 1.8 mm can be fabricated for applications over 15 GHz, with reflection loss more than −25 dB for specific frequencies, by controlling the molar ratio of the substituted ions.