Young-Min Kang

Grain growth behavior of Ba1.5Sr1.5Co2Fe24O41 flakes in molten salt synthesis and the magnetic properties of flake/polymer composites

Single-phase Ba1.5Sr1.5Co2Fe24O41 (Ba1.5Sr1.5Z) hexaferrite flakes were synthesized using a two-step grain growth process, involving a calcination process and molten salt synthesis. Geometric parameters such as aspect ratio and the degree of agglomeration can be controlled by tuning this calcination-molten salt method. The morphological evolution of the flakes was explained using the concept of mixed-control grain growth, i.e., a combination of diffusion for growth and interface reactions, which is a growth mechanism for a faceted interface. The single-phase Ba1.5Sr1.5Z flake particle with high aspect ratio turned out to be a good candidate of soft magnetic inclusion, through an investigation of the correlation between material composition, magnetic behavior, and particle morphology.