Coercivity map in perpendicular media investigated by using in situ magnetic force microscopy

The spatial distribution of coercivities in a CoCrPt-SiO2 granular perpendicular magnetic recording medium was measured by using in situ magnetic force microscopy. The coercivity map that shows the spatial distribution of coercivities was obtained at 1 kOe intervals in the medium. The "local" coercivities within microscopic areas of less than 100 nm square were evaluated with a good reproducibility. Measuring coercivity map will become a technique for investigating the influence of the spatial distribution of coercivities on the medium noise in perpendicular recording. (C) 2004 American Institute of Physics.