Hexagonal ferrite powder, magnetic recording medium, and method for producing hexagonal ferrite powder

摘要

The hexagonal ferrite powder has an activation volume of greater than or equal to 800 nm3 but less than 1,200 nm3, a rare earth atom content falling within a range of 0.5 to 8.0 atom % per 100 atom % of iron atoms, and a localized presence of rare earth atoms in the surface layer portion, as well as is in the form of ellipsoidal powder.