Flux closure in magnetic force microscope tips

This work considers the effect of MFM tip magnetisation distribution on force gradient images of Co/Pt perpendicular anisotropy multilayer materials. In particular it is shown that a pyramidal tip with a Co coating which is thought to contain closure domain structures produces substantially different images from single domain CoPt coated tips. Modelling results are also presented which support the closure domain hypothesis. If is concluded that the small effective volume of the closure tip produces valuable results in terms of resolution and image clarity