Microwave dielectric properties of M-type barium, calcium and strontium hexaferrite substituted with Co and Ti

Suitable ferrite components are designed for use in systems like radar, satellite uplinks, industrial heaters or dryers and nuclear systems which employ high power microwaves. Ferrites are also used as microwave absorbers. Radar absorbing paint made from ferrites can be used to coat military aircraft for stealth operation. In this study, some hexaferrites have been synthesized and characterized for their possible use at high frequencies. Three series of M type hexagonal ferrites having the general formula MeFe12O19 in which Me was Ba2+, Sr2+ or Ca2+ and Fe3+ ions were replaced partly by Co2+Ti4+ ions were chosen for synthesis and study. The microwave dielectric constants of these hexaferrites has been measured in the X band of the microwave frequency range after successively increasing the amount of substituted ions in the ferrites. The variation of Complex Permittivity of these hexaferrites with change in composition as well as change in frequency has been measured in this frequency range. Important inferences have been drawn using theoretical concepts.