Extremely high linear density recording by perpendicular magnetization

High output and high linear density recording of over 300 kFRPI was obtained utilizing a composite perpendicular media of Co-Cr system alloy. It was found that the medium thickness exhibited a significant effect on the output. Higher output and lower noise were also obtained for media with higher Cr content. This may be related to the decrease in the magnetic domain size in the media. Finally, a high linear density signal of more than 1000 kFRPI was detected and an ultrahigh areal density recording of 29.6 Gbit/in(2) was observed by MFM for a Co-Cr composite medium with thickness of 50 nm.