High density perpendicular recording at very low flying height under rarefied pressure condition

To attain higher recording densities in perpendicular rigid disk drives, it is important to decrease the flying height. The relation between read/write characteristics and the flying height under reduced ambient pressures was measured. The reduced pressure allows the flying height to be freely controlled. The limit of recording density is evaluated from the viewpoint of the signal-to-noise ratio (SNR). The result is a recording density of over 600 kb/mm² with SNR of 26 dB from a combination of a thin-film head and a CoCr/FeNi double-layered medium with the very low flying height of about 0.05 μm. This recording density shows the potential of combining CoCr/FeNi media of thin-film heads in rigid disk drives