3. Recent advances in magnetic force microscopy: Quantification and in Situ field measurements

Abstract

Publisher Summary This chapter provides an overview of magnetic force microscopy (MFM) and highlights some of the most useful models in image interpretation. MFM produces a two dimensional (2D) image of the derivatives of the local magnetic field from the surface. The lateral resolution is typically 100 nm, although 25 nm and smaller magnetic features have been reported under certain conditions. MFM uses a cantilever probe containing a magnetic tip, which is oscillated near its resonance frequency and scanned at a constant height above the sample. The variation of the magnetic interaction at different regions of the sample changes the resonance frequency of the cantilever, which is manifested as an amplitude or phase change of the cantilever oscillation. The magnetic image is obtained by recording one or more of these parameters point by point as a function of the lateral position of the tip. With the aid of computer graphics, the raw data array is converted to a gray-scale or some pseudo 2-D plot to generate a two-dimensional rendition of the surface magnetic features.