Separation of topographic features from magnetic images has been an issue for the past two decades in magnetic force microscopy (MFM). The frequent pickups of the topographic features are interpreted as transitions of the tip between bistable states of the tip-sample assembly in the noncontact and tapping regions. MFM using electrostatic force modulation demonstrates the separation of the topographic features from the magnetic images by removing the tapping state from the bistable states through the introduction of a capacitive coupling.
Kim, Byung I.. (2009). "Separation of Topographic Features from Magnetic Force Images Using Capacitive Coupling Effect". Review of Scientific Instruments, 80(2), 023702-1 - 023702-4. http://dx.doi.org/10.1063/1.3077151