MAGNETIC FINE PARTICLE POWDER FOR MAGNETIC RECORDING MEDIUM, AND MANUFACTURING METHOD OF THE SAME

摘要

PROBLEM TO BE SOLVED: To provide magnetic fine particle powder for magnetic recording medium and method of manufacturing the same, and more particularly to provide magnetic fine particle powder for magnetic recording medium capable of reducing influence of heat fluctuation accompanied with making the magnetic particle powder to finer particles.

SOLUTION: A method for obtaining the magnetic fine particle powder for magnetic recording medium, wherein the average plane diameter of hexagonal ferrite particle powder is 10-50 nm and the existence ratio of super-fine particle having a plane diameter of less than 10 nm to whole particles is 15% or less, includes the steps of: dispersing the hexagonal ferrite particle powder in water to be aqueous suspension liquid; dissolving a super-fine particle component in the hexagonal ferrite particle powder on condition of 3.5 or less pH value and 20-100°C of temperature ranges; and washing and drying the remaining hexagonal ferrite particle powder.

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