Magnetite-Silver Core–Shell Nanoparticles: Synthesis, Characterizes, and Optical Properties

Fe3O4 and Fe3O4/Ag core–shell nanocomposite powders were synthesized via the co-precipitation method. The structure, microstructure, magnetic, optical properties of studied. XRD patterns UV–Vis spectra showed that nanostructure particles successfully synthesized. AFM MFM mode micrographs confirm formation in nano-scale range. Both composite represented superparamagnetic behavior due to nanosized particles. Furthermore, in-situ synthesis Ag on surface magnetite nanoparticles increased particle size, resulting a decrease saturation magnetization. Moreover, based Maxwell-Garnet effective medium theory, theoretical model was developed determine suspended nanoparticles. A very good agreement found between experimental results. In addition, local electric field particles, evaluated using numerical finite element method, core might be amplified up 20 times at symmetrical SPR wavelength mode, depending silver shell thickness.