Evolution of Electronic and Magnetic Properties of Nominal Magnetite (Fe₃O₄) Nanoparticles Under Pressure-An XMCD Study

Nanoparticles(NPs) are being extensively studied due to differences in atomic, electronic, magnetic, physical and chemical properties compared to their bulk. As the particle dimensions approach the nanoscale, a large fraction of atoms will be near the surface, resulting in changes in behavior compared to larger particles. Studies of NPs at extreme conditions have seen further modifications of these properties. Magnetite (Fe₃O₄) is a naturally occurring mineral and have particles in the nano-sized region. We investigate the evolution of electronic and magnetic properties of 6 nm nominal magnetite (Fe₃O₄) NPs under pressure. Similar investigations on bulk magnetite have been conducted previously, however, only a little is known regarding NPs. Well characterized NPs were prepared using chemical coprecipitation method. We used x-ray magnetic circular dichroism (XMCD) and x-ray absorption spectroscopy (XAS) at Fe K-absorption edge, to investigate electronic and magnetic properties of NPs under pressure, at the Advanced Photon Source, Argonne National Laboratory. The results of this investigation will be presented.