Synthesis of monosized magnetic-optical AuFe alloy nanoparticles

Abstract

We report the preparation and characterization of multifunctional AuFe alloy nanoparticles of three compositions, Au0.25 Fe0.75, Au0.5 Fe0.5, and Au0.75 Fe0.25, by a polyol process. It is found that the fusion of the two elements into one nanostructure entity retains the optical and magnetic properties of the individual components. The x-ray diffraction and transmission electron microscopy analyses confirm the formation of the alloy nanostructure with a narrow distribution of particle sizes and provides the detailed structural arrangements. The magnetic investigation shows the superparamagnetic or soft ferromagnetic behavior of the nanoparticles at room temperature, whereas the UV-visible measurements display the variation of the absorption bands at ∼560 nm. The AuFe nanoparticles are rendered water soluble after thiolation. © 2008 American Institute of Physics.