Magnetic recording powder, method of manufacturing thereof and application thereof

摘要

A matnetic recording powder comprising a hexagonal barium ferrite substituted with a coercive force control element. This magnetic powder is preliminarily treated with sulfate ion-containing water so as to convert any free barium ions in the magnetic powder to a water insoluble compound such as BaSO4 or BaS2O7. There is also proposed a magnetic recording medium having a magnetic layer containing such a magnetic powder as mentioned above.