HEXAGONAL FERRITE POWDER, MAGNETIC RECORDING MEDIA AND MANUFACTURING METHOD OF HEXAGONAL FERRITE PO

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PROBLEM TO BE SOLVED : To provide a hexagonal ferrite powder capable of manufacturing magnetic recording media capable of exhibiting excellent electromagnetic conversion property and less in reduction of regeneration output in repeated regeneration. SOLUTION : There is provided a hexagonal ferrite powder which has activation volume of 800 nm3 or more and less than 1200 nm3, preferably 850 to 1150 nm3, rare earth atom percentage content of 0.5 to 8.0 atom%, preferably 0.5 to 6.0 atom%, especially preferably 1.0 to 4.5 atom% based on 100 atom% of an iron atom, anisotropy constant Ku of 1.5×104 J/m3 or more and rare earth atom surface part uneven distribution and is oval powder. There is provided hexagonal ferrite having the rare earth which is one or more kind selected from Y, La, Sm, Yb and Nd. There is provided magnetic recording media using the ferrite powder. there is provided a manufacturing method of the hexagonal ferrite powder. SELECTED DRAWING : Figure 1 COPYRIGHT : (C)2018, JPO&INPIT