Near surface magnetic domain observation with ultra-high resolution.

Near field magnetic force microscopy (NF-MFM) has been demonstrated to locally observe the magnetic fine structures in nanosized recording bits at an operating distance of 1 nm. The nanoscale magnetic domains, the polarity of surface magnetic charges, as well as the 3D magnetic fields leaking from the bits are investigated via NF-MFM with a soft NiFe tip. A Fourier analysis of the images suggests that the magnetic moment can be determined locally in a volume as small as 5 nanometers. The NF-MFM is crucial to the analysis of surface magnetic features and allows a wide range of future applications, for example, in data storage and biomedicine.