Magnetic properties of topochemically sintered barium hexaferrite

Abstract

This communication describes the method of topochemical reaction sintering for the production of barium hexaferrite. Topochemical reaction sintering overcomes crucial process steps that are used in the conventional wet magnetic compaction method, such as calcination, wet grinding, and wet magnetic compaction, Chemical reaction sintering of the above-mentioned ferrite has been performed in air and under vacuum. Barium hexaferrite that has been topochemically sintered in air at a temperature of 1473 K for 60 min shows a maximum magnetic energy product ((BH)(max)) of 6.56 kJ/m(3), whereas barium hexaferrite that has been topochemically sintered at a temperature of 1423 K for 30 min under vacuum (10(-2) mm Hg (similar to 0.133 Pa)) shows (BH)(max) = 7.6 kJ/m(3). The variation of the magnetic properties of the topochemically sintered ferrites is interrelated to process variables such as temperature and sintering duration (time).