METHOD OF MANUFACTURING HEXAGONAL FERRITE MAGNETIC POWDER, MAGNETIC RECORDING MEDIUM AND METHOD OF MANUFACTURING THE SAME

摘要

An aspect of the present invention relates to a method of manufacturing a hexagonal ferrite magnetic powder comprising preparing a melt by melting a starting material mixture, wherein the starting material mixture comprises at least one hexagonal ferrite-forming component and glass-forming component comprising at least one B2O3 component and a content of the B2O3 component in the mixture ranges from 15 to 27 mole percent in terms of B2O3; rapidly cooling the melt to obtain a solid having a saturation magnetization level of equal to or lower than 0.6 A.m2/kg; and heating the solid to a temperature range of 600 to 690° C. and maintaining the solid within the temperature range to precipitate a hexagonal ferrite magnetic powder having an average plate diameter ranging from 15 to 25 nm.