A new variable external field magnetic force microscope is introduced here. The most
outstanding feature of the system is its capability to perform stable images under a variable
external magnetic field that can be applied both in in-plane and out-of-plane directions. The
performances of the microscope are illustrated for four different suitable selected samples:
highly oriented pyrolytic graphite, longitudinal magnetic storage media, FePt thin films with
in-plane anisotropy and Ni nanowires with axial easy axis embedded on a ceramic matrix …