Magnetic recording measurements of high coercivity longitudinal media using magnetic force microscopy (MFM)

Longitudinal magnetic recordings written on high coercivity medium (Hc=2500 Oe) were investigated using magnetic force microscopy (MFM). Recorded tracks with bit density up to 6000 fr/mm were investigated. A variety of qualitative information about the recorded tracks and domain structure in the medium was obtained. It was determined that the recorded bits strongly interacted with domains in the medium at the track edges, causing severe jitter. Also bit bending due to the head field was observed. A new method for the quantitative analysis of recorded tracks was used. Using this method, recording signal and medium signal-to-noise ratio were calculated from MFM data. Parameters obtained in this way showed excellent agreement with signal and signal-to-noise ratio obtained from the recording measurement using a MR head.