Figure 1
From: “Magnetic Force Microscopy and Energy Loss Imaging of Superparamagnetic Iron Oxide Nanoparticles”
Simplified sketch of the tip-particle magnetic layout in a dipole-dipole model, indicating the different distance terms (not at scale).
Magnetic dipoles (black arrows) are modeled as located in the center of a SP NP having diameter dm and in the center of a sphere with diameter dt approximating the tip apex, while d0 represents the thickness of a non magnetic layer on the particle. Therefore in this scheme the dipole-dipole distance is easily obtained adding z0 = dm/2+dt/2+d0 to the physical distance s.
