Switching Magnetization Magnetic Force Microscopy — An Alternative to Conventional Lift-Mode MFM

In the paper we present an overview of the latest progress in the conventional lift-mode magnetic force microscopy (MFM) technique, achieved by advanced MFM tips and by lowering the lift height. Although smaller lift height offers improved spatial resolution, we show that lowered tip-sample distance mixes magnetic, atomic and electric forces. We describe an alternative to the lift-mode procedure - Switching Magnetization Magnetic Force Microscopy [SM-MFM], which is based on two-pass scanning in tapping mode AFM with reversed tip magnetization between the scans. We propose design and calculate the magnetic properties of such SM-MFM tips. For best performance the tips must exhibit low magnetic moment, low switching field, and single-domain state at remanence. The switching field of such tips is calculated for Permalloy hexagons.