Synthesis and characterization of nanocrystalline Ba3Co0.9Cu1.1Fe24O41 powder and its application in the reduction of radar cross-section

There has been a growing and widespread interest in the development of radar absorbing materials (RAM). Z-type hexaferrite is one of the most complex compounds in the family of hexaferrites that may be used in many applications. In this work, the citrate sol-gel process under an inert atmosphere was used to obtain the nanocrystalline Ba3Co0.9Cu1.1Fe24O41 powder to be used as RAM. Cu2+ ions were incorporated into the structure of Ba3Co2Fe24O41 and, consequently, low temperature sintering and good magnetic properties were achieved. Composites of Ba3Co2Fe24O41 with polychloroprene (CR) were obtained for microwave absorption measurements by the transmission/reflection method, using a waveguide medium for the S- band and X-Ku bands. The 80:20 nanocomposite of Ba3Co0.9Cu1.1Fe24O41:CR with 3.0 mm thickness exhibited the best performance as a RAM for the X-band, with 99.50% microwave absorption at 9.5 GHz.