Low noise property of Co-Cr-M perpendicular magnetic recording media at high recording density

MFM observation of recorded patterns was performed to understand a relationship between a magnetic cluster size and a recording property for high density perpendicular Co-Cr-M films. The signal intensity obtained by FFT analysis for MFM images of the media was maintained at high levels up to a linear density as high as 400 kFRPI. Magnetic cluster size did not change with the recorded densities. Since the signal intensities were deteriorated at higher recording density where a bit size was compatible to the magnetic cluster size, the medium recording resolution, D-50, became limited by the cluster size. MFM observation proved that the recorded magnetic patterns of a linear density as high as 500 kFRPI and an areal density of 25 Gbit/in(2) was discernible for a Co-Cr-Nb-Pt medium.