Reduced-area magnetic bit recording and detection using magnetic force microscopy based on application of bidirectional magnetomotive force

The size of the magnetization region of perpendicularly recorded bits is reduced using a method based on magnetic force microscopy (MFM). A new bit is written over part of the previous bit by using an alternating magnetomotive force. Detected force gradient trajectories and images reveal that this method successfully reduces the bit cell size down to half that of an isolated bit. A comparison of images of MFM-recorded bits and bits recorded using a thin-film head suggests that the recording density is limited mainly by the writing ability of the MFM tip