HEXAGONAL CRYSTAL STRONTIUM FERRITE POWDER FOR MAGNETIC RECORDING AND MAGNETIC RECORDING MEDIUM

PROBLEM TO BE SOLVED : To provide hexagonal crystal strontium ferrite powder for magnetic recording and a magnetic recording medium, capable of minimizing into fine particles of hexagonal strontium ferrite powder and suppressing reduction in regeneration output during repeated regeneration. SOLUTION : A hexagonal strontium ferrite powder for magnetic recording has an activation volume in a range of 800 to 1500 nm3, a rare earth atom content of 0.5 to 5.0 atom% with respect to 100 atomic% of an iron atom, and has an uneven distribution of the rare earth atom content (uneven distribution of a surface layer part). A magnetic recording medium has a magnetic layer containing the magnetic recording hexagonal strontium ferrite powder and a binder. SELECTED DRAWING : None COPYRIGHT : (C)2019, JPO&INPIT