Controlled Synthesis of Fe3O4/Ag Core–Shell Composite Nanoparticles with High Electrical Conductivity

The presented method provides an easy processing route to synthesize Fe3O4/Ag core–shell composite nanoparticles. Their structures were characterized by x-ray diffraction and transmission electron microscopy. The average size of the Fe3O4 core and Ag shell was about 32.0 nm and 5.0 nm (or 28.0 nm), respectively. Furthermore, magnetic measurements showed that the composite nanoparticles exhibited typical superparamagnetic behavior, specific saturation magnetization of ca. 24.0 emu/g, and intrinsic coercivity of 106.0 Oe. At the same time, high conductivity (64.7 S/cm) of the composite nanoparticles was also observed. This method provides an opportunity to synthesize other core–shell (Fe3O4) nanoparticles in a single step.