Induction of enhanced magnetic behavior in gold, silver, and copper by doping with SrFe12O19 nanoparticles

Enhanced magnetic moment is induced in nonmagnetic metals. Specifically, gold, silver, and copper are rendered with bulk magnetic behavior by doping these metals with ferrimagnetic strontium hexa-ferrite ($\mathrm{SrF}{\mathrm{e}}_{12}{\mathrm{O}}_{19}$) nanoparticles. The doped metals exhibit classical macroscopic permanent magnetic properties. Remarkably, detailed magnetization studies reveal that the saturation moments $({M}_{S})$ of these materials are enhanced by a factor of 5--8 compared to pure $\mathrm{SrF}{\mathrm{e}}_{12}{\mathrm{O}}_{19}$ nanoparticles. The enhancement order is $\mathrm{Cu}g\mathrm{Ag}g\mathrm{Au}$. A mechanism is suggested for the enhancement and for its order, based on a full materials characterization of these $\mathrm{SrF}{\mathrm{e}}_{12}{\mathrm{O}}_{19}$@Metals.