| 摘要 |
According to one embodiment of the present invention, plate-shaped high crystalline ferrite magnetic powder is R-Fe-O ferrite magnetic powder wherein the R is selected one or more among groups formed of Sr, Co, and Ba and has 0.1-10 μm of a grain size. Also, a method to manufacture high crystalline ferrite magnetic powder comprises: a step of mixing ferrite precursors and salts; a step of forming droplets by spraying the mixture; and a step of growing ferrite grains by passing the droplets through a reaction chamber with carrier gas. The magnetic power facilitates magnetization, has excellent arrangement in an axial direction, and prevents agglomeration between the grains. According to the other embodiment of the present invention, bimodal ferrite powder comprises magnetic powder (First powder) according to one among claim 1-5 and ferrite nanopowder (second powder) with 0.01-0.5 μm of a grain size. Also, the present invention relates to a bimodal ferrite sintered magnet manufactured using the same. Furthermore, a method to manufacture a sintered magnet comprises: a step of manufacturing slurry by mixing the bimodal ferrite powder with a water-based solvent; a step of applying a magnetic field to the slurry; and a step of sintering the slurry to which the magnetic field is applied. The sintered magnet has high sintered density and excellent coercive force and remained magnetic flux density to be applied to electronic devices requiring miniaturization and weight lightening. |
