'Characteristics of mesoscopic ferromagnetic rings in magnetic fields and their potential use in phase contrast electron-microscopy'- Gerard Higgins

Flux-closed vortex states of mesoscopic rings can be used to introduce a phase difference between electrons passing through the ring and those passing outside it, by the Aharonov-Bohm effect. Thus they are candidates for use as phase plates in transmission electron-microscopy. The stability of the vortex state is of critical importance. Micromagnetic simulations have been carried out using OOMMF on rings with different shapes (circular and D-shaped), magnetic anisotropies (including grains), widths, diameters, thicknesses and cellsizes.