Magnetic force microscopy is a powerful tool for high-resolution magnetic imaging of most data storage media. As the density of magnetic media is higher, the bit becomes smaller than the wavelength of light, so optical techniques can not resolve it. General MFM is capable of imaging the magnetic domain of several tens of nanometers. Also, MFM is almost simultaneous with measuring the surface characteristics of topography and roughness of the same area with sub-angstrom vertical resolution.
Left: The topography of a commercial hard disk measured by Non-contact AFM Right: The image
is simultaneously acquired using magnetic force on the same area. Protrusion(bright)
and depression(dark) in the MFM image clearly represent the magnetic
bit and height profile. Rms roughness in topography is 8.62nm. |
