Attempt for Fabrication of Acicular Hexagonal Ferrite Particles Elongated in the c-axis Direction

Barium ferrite particles were synthesized from acicular α-Fe2O3 particles grown in the c-axis direction. The synthesis was carried out by the flux method, in which acicular α-Fe2O3 particles reacted with BaCO3 in NaCO3 flux. The acicular-shaped BaFe12O19 particles grown in the c-axis direction were obtained. The acicular shape consisted of aggregates of plate-like particles stacked along the c-axis. The platelet-shaped BaFe12O19 particles prepared from spherical α-Fe2O3 under the same synthesis conditions exhibited a smaller coercivity than the acicular BaFe12O19 particles synthesized in this study. Therefore, it can be inferred that the shape anisotropy has an effect on the magnetic properties of the acicular particles.