Magnetic Force Microscopy for Magneto-Optic Bit Imaging

An introduction to magnetic force microscopy (MFM) is presented which provides the information necessary to make simple interpretations of MFM images. Images of bits written on standard 1X format magneto-optic (MO) disks (sold commercially) are shown and discussed qualitatively. When the MFM tip is close to the surface of the magnetic film (reflector coating removed), the near field is detected such that the transition between oppositely magnetized regions can be seen. At greater distances where only the far field is sensed, the bits can be imaged, but the edges are not resolved. This work shows that for highest resolution MFM imaging of the bit edges, the reflector coating must be removed.