A novel analysis method for noise of perpendicular recording media

An in-field magnetic force microscopy (MFM) observation technology was introduced to study media noise in perpendicular recording medium. Magnetization reversal field (HR) distribution of the recording medium could be mapped by this technology. We have extracted media noise signal image from recording pattern. The noise signal image was converted to a contour image, in which peak areas represented high-noise areas. To clarify the relationship between HR distribution and the media noise, we novelly combined the contour with the HR-map. The results show that the media noise mostly gets generated in the lower-HR areas, which indicates the lower-HR area is one of the important origins of the media noise. For comparison, a simulation work was also performed by introducing a model based on experimental parameters. The simulation agreed with experimental results very well.