  Since the invention of the atomic force microscope (AFM) in 1986, there has
been a drive to apply this scanning probe technique or a form of this technique
to various disciplines in nanoscale science. Magnetic force microscopy (MFM) is
a member of a growing family of scanning probe methods and has been widely used
for the study of magnetic materials. In MFM a magnetic probe is used to
raster-scan the surface of the sample, of which its magnetic field interacts
with the magnetic tip to offer insight into its magnetic properties. This
review will focus on the use of MFM in relation to nanoparticle
characterization, including superparamagnetic iron oxide nanoparticles,
covering MFM imaging in air and in liquid environments.
