Highly Magnetic Core-Shell Nanoparticles with a Unique Magnetization Mechanism

Magnetic nanoparticles (MNPs) with high magnetic moments and very small size are under active development, since such materials have growing uses in biotechnology and medicine.[1] Ferromagnetic metals, rather than their corresponding oxides, have been suggested as an ideal constituent for MNPs for their superior magnetization.[2] Unfortunately, monometallic MNPs typically require protective layers to prevent progressive oxidation. To date, however, most core/shell approaches have yielded suboptimal magnetization, as the shell was formed either by artificially oxidizing the core[3,4] or by coating it with non-magnetic materials.[5]