| abstract |
The present invention relates to a hexagonal ferrite particle powder for a magnetic recording medium, and relates to a hexagonal ferrite particle powder having excellent magnetic properties and effective in reducing noise in a magnetic recording medium. SOLUTION: An average plate surface diameter (D TEM ) of hexagonal ferrite particle powder is 10 to 30 nm, and a single crystallinity [ratio of average plate surface diameter (D TEM ) and crystallite diameter (D X ) (D TEM / D X )] in the range of 0.8 to 1.2, and each element of the platinum group elements (ruthenium, rhodium, palladium, osmium, iridium and platinum) contained in the hexagonal ferrite particle powder. It is a hexagonal ferrite particle powder for magnetic recording media having a total amount of 10 ppm or less and Ca of 1000 ppm or less. [Selection figure] None |