Magnetic force microscope

Magnetic force microscopy (MFM) is a variety of atomic force microscopy, in which a sharp magnetized tip scans a magnetic sample; the tip-sample magnetic interactions are detected and used to reconstruct the magnetic structure of the sample surface. Many kinds of magnetic interactions are measured by MFM, including magnetic dipole–dipole interaction. MFM scanning often uses non-contact AFM (NC-AFM) mode. Magnetic force microscopy (MFM) is a variety of atomic force microscopy, in which a sharp magnetized tip scans a magnetic sample; the tip-sample magnetic interactions are detected and used to reconstruct the magnetic structure of the sample surface. Many kinds of magnetic interactions are measured by MFM, including magnetic dipole–dipole interaction. MFM scanning often uses non-contact AFM (NC-AFM) mode. In MFM measurements, the magnetic force between the sample and the tip can be expressed as where m → {displaystyle {vec {m}},!} is the magnetic moment of the tip (approximated as a point dipole), H → {displaystyle {vec {H}},!} is the magnetic stray field from the sample surface, and µ0 is the magnetic permeability of free space.