Abstract
Orientation degree of strontium ferrite particles in a magnetic field at water-based wet-pressing stage was investigated from the viewpoint of calcining temperature and dispersant addition. In the case of no dispersant addition, the orientation degree was low especially at low calcining temperature (1150°C and 1200°C), at which the particle size was under micron. Increasing the calcining temperature, the orientation degree noticeably increased. On the other hand, we found that the orientation of the submicron sized particles was much improved by addition of calcium gluconate as a dispersant and then the orientation degree was almost independent of calcining temperature. It was predicted that calcium gluconate effectively deagglomerated submicron sized particles of strontium ferrite. Therefore addition of calcium gluconate enabled to produce high-performance ferrite magnets with both high coercivity and high remanence.
