This communication describes the method of topochemical reaction sintering
for the production of barium hexaferrite. Topochemical reaction sintering o
vercomes crucial process steps that are used in the conventional wet magnet
ic compaction method, such as calcination, wet grinding, and wet magnetic c
ompaction, Chemical reaction sintering of the above-mentioned ferrite has b
een performed in air and under vacuum. Barium hexaferrite that has been top
ochemically sintered in air at a temperature of 1473 K for 60 min shows a m
aximum 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)(m
ax) = 7.6 kJ/m(3). The variation of the magnetic properties of the topochem
ically sintered ferrites is interrelated to process variables such as tempe
rature and sintering duration (time).