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

Abstract

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.