Microstructure characterization and properties of chemically synthesized Co(2)Z hexaferrite

Powders having stoichiometric composition of Co(2)Z (Ba3Co2Fe24O41) were pr epared by gel self-propagating method and processed at different temperatur es to study phase evolution process. Unlike other ferrites. Co(2)Z hexaferr ite was not synthesized directly by gel self-propagating technique. but was formed gradually from some intermediate phases due to its complicated crys talline structure. After Z-type phase formed at relatively low temperatures of 1200 degreesC, the powders were annealed at temperatures lower than 120 0 degreesC. It was found that, once formed, this phase was quite stable. At the same time, the morphology and distribution of hexagonal particles was improved. and ceramic samples thus achieved from the relative powders prese nted excellent ultrahigh frequency magnetic properties. (C) 2001 Published by Elsevier Science Ltd. All rights reserved.