Enhancement Effect of the Coercive Force of Barium Ferrite by Grinding and Annealing Treatments

Abstract

Coercive force of barium ferrite is much influenced by a grinding process with a planetary ball mill or an automatic glass mortar. Influential factors on this occasion have been analyzed by measuring the normal magnetic hysteresis loop curve, remainder magnetizaition curve, and X-ray diffraction pattern of various samples prepared by calcining, milling, and annealing barium ferrite.
The coercive force of barium ferrite that was ground with a planetary ball mill increased or decreased, b ut the pretreatment with the automatic glass mortar led only to the increase of the coercive force. It was disclosed that the enhancement of the coercive force is mainly caused by the orientation of crystal plate and the reduction of the coercive force by the random distortion of the crystal lattice.