Magnetic core shell nanostructures with plasmonic properties

Abstract

The gold nanoparticle coated cobalt-silica core-shell nanospheres have been synthesized via a multi-step, solution based chemical approach. While the plasmonic characteristics of gold nanoparticles (AuNPs) are retained in core shell configuration, the magnetic properties of core shell system change significantly after AuNP coating. It is found that the coercivity of magnetic core-shell significantly reduces after AuNP coating and system could not attain magnetic saturation at 300 K (even at large field of 5 T). At low temperature (10 K), AuNP coated cobalt-silica coreshell nanospheres exhibit reduced magnetization (Ms=4.3 emu/g) compared to bare cobalt-silica core-shell system (Ms=6 emu/g).