Magnetic force microscopy of ferromagnetic nanoparticles formed in Al2O3 and SiO2 by ion implantation

Magnetic force microscopy (MFM) has been used to investigate the properties of ferromagnetic FePt nanoparticles produced by the implantation of Fe and Pt ions into single-crystal Al2O3 or fused SiO2 followed by thermal processing. The MFM results are compared to cross-section and plan view transmission electron microscopy images of the same samples. We demonstrate that MFM can detect magnetism in nanosized particles that are situated several hundred nm below the sample surface. MFM is shown to be a promising tool for studying the characteristics of magnetic nanoparticles produced by ion implantation.