Magnetic Properties of Bi and Si Oxides-Doped M-Type Barium Ferrite

Abstract

Barium ferrite doped with Bi and Si oxide was sintered densely at a low temperature of approximately 900°C, suppressing grain growth. This ferrite magnet had a two-phase structure comprising a barium ferrite phase and an amorphous bismuth silicate phase. We investigated the relationship between the magnetic properties and SiO2 content and found that the coercive force increased in proportion to the SiO2 content. It was suggested that the coercive force increased because each grain was magnetically shielded by a grain boundary phase.