Plasmon induced magneto-optical enhancement in metallic Ag/FeCo core/shell nanoparticles synthesized by colloidal chemistry

The combination of magnetic and plasmonic materials and their nanostructurization have revealed a prominent pathway to develop novel photonic materials for the active control of the light polarization using a magnetic field. Until now, physical growth methods have been the only exploitable approach to prepare these types of nanostructures. Here, we demonstrate the chemical synthesis of magneto-plasmonic core/shell nanocrystals with enhanced magnetic control of optical properties comparable to the best results reported for nanostructure growth by physical methods. Ag/FeCo core/shell nanocrystals were synthesized using a combination of hot injection and polyol approaches, demonstrating that the well-defined structures of both components, their interface and the optimized morphology, where the plasmonic and magnetic components are placed in the core and the shell regions, are responsible for the observed large enhancement of magnetic control of light polarization. Therefore, there is a possibility to develop tunable magneto-optical materials from hybrid magneto-plasmonic structures synthesized by chemical methods.