Reduced Magnetism in Core-Shell Magnetite@MOF Composites

The magnetic susceptibility of synthesized magnetite (Fe3O4) microspheres was found to decline after the growth of a metal–organic framework (MOF) shell on the magnetite core. Detailed structural analysis of the core–shell particles using scanning electron microscopy, transmission electron microscopy, atom probe tomography, and57Fe–Mossbauer spectroscopy suggests that the distribution of MOF precursors inside the magnetic core resulted in the oxidation of the iron oxide core.