The effects of processing conditions on the properties of polycrystalline Bi3-2xCa2xFe2Fe3-xVxO12ferrites

Results of studies on processing conditions for Bi3-2xCa2xFe2Fe3-xVxO12ferrite are given. The advantages of using oxygen atmospheres during sintering are detailed. These advantages relate not only to the magnetic and dielectric properties but also to the final density of the sintered piece. Densities of 99 percent of the X-ray theoretical value were obtained with oxygen sintering; whereas, only 96 percent was obtained by sintering in air. The narrow range of sintering temperatures normally found for this class of materials is seen to be extended by the use of oxygen sintering. The reasons for these improvements are given in terms of suppression of liberated oxygen. Volatilization of bismuth occurs, if at all, at very low levels during the final firing. Also, changes in magnetization with increasing sintering temperature are inconsistent with increasing loss of bismuth.