| abstract |
The present invention provides a magnetic powder capable of simultaneously improving magnetic characteristics including SNR of a magnetic recording medium and improving durability. The above-mentioned problems are composed of magnetic particles in which aluminum hydroxide is deposited on the surface of hexagonal ferrite particles, and the Ba / Fe molar ratio is 0.080 or higher, the Bi / Fe molar ratio is 0.025 or higher, This is achieved by a hexagonal ferrite magnetic powder for magnetic recording media having an Al / Fe molar ratio of 0.030 to 0.200. The activation volume Vact is preferably 1300 to 2000 nm 3 . Particularly preferred are those having a coercive force Hc of 159 to 287 kA / m (about 2000 to 3600 Oe) and a coercive force distribution SFD of 0.3 to 1.0. One or more of a divalent transition metal M1 and a tetravalent transition metal M2 can be contained as an element for substituting Fe in hexagonal ferrite. [Selection figure] None |