Ferromagnetic spots in graphite produced by proton irradiation

A proton microbeam produces ferromagnetic spots on a highly oriented graphite surface. The Figure shows the topography and the magnetic force microscopy (MFM) images obtained after irradiating the surface with a beam size of 1 mum x 1 mum and a dose of 0.098 nC mum(-2). The strength of the magnetic signal is only a factor of similar to 10 smaller than that obtained on Fe particles.