Review on Point Dipole Approximation in Magnetic Force Microscopy

Image interpretation in magnetic force microscopy (MFM) requires details information about the internal microstructure the ferromangetic tip used for probing the surface microfield of a sample. Since these information are generally not experimentally available, image interpretation is more speculative than rigorously quantitative at the present time. This theoretical analysis confirms by a simple criterion that MFM image interpretation\ud can be perform in terms of point dipole probing provided that some experiment constraints are satisfied. The validity of the criterion is demonstrated for various experimentally relevant example. Starting from tip transfer function (TTF), a minimum detectable wavelength will be used as a measure for the lateral resolution of the instrument. This minimum detectable wavelength will determine the detector noise level in the instrument’s configuration