Electromagnetic properties and microwave absorbing characteristics of doped barium hexaferrite

M-type barium hexaferrite BaFe12-x(Mn0.5Cu0.5Ti)(x/2)O-19 (x varying from 0 to 3 in steps of 1) have been synthesized by the usual ceramic sintering method. The ferrite powders possess hexagonal shape and are well separated from one another. The powder of these ferrites were mixed with polyvinylchloride plasticizer to be converted in to a microwave absorbing composite. X-ray diffraction (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, the magnetoplumbite structures for all the samples have been formed. The sample having higher magnetic susceptibility and coercivity exhibits a larger microwave absorbing ability. Also, the present investigation demonstrates that microwave absorber using BaFe12-x(Mn0.5Cu0.5Ti)(x/2)O-19 (x = 2 and 3)/polyvinylchloride can be fabricated for the applications over 15 GHz, with reflection loss more than -25 dB for specific frequencies, by controlling the molar ratio of the substituted ions. (c) 2005 Elsevier B.V. All rights reserved.