The potential of magnetic force microscopy for in-situ investigation of nanophase iron in lunar dust

Lunar dust is known to contain nanophase iron (np-Fe), which is suspected to be toxic. These magnetic nanoparticles have a diameter in the lower nanometre range and are enclosed in a glassy rim produced by space weathering. The np-Fe must be exposed in order to develop its toxicity and, hence, an instrument for in-situ assessing the location of np-Fe on soil particles would be needed. This contribution proposes a method for such in-situ analysis of np-Fe and its distribution on dust and soil particles. Magnetic nanophase iron oxide is used to demonstrate that magnetic force microscopy can detect single imbedded magnetic nanoparticles of 30 nm and differentiate them from magnetic or non-magnetic nanoparticles at the surface.