Size-controlled synthesis, microstructure and magnetic properties of Ni nanoparticles

Ni nanoparticles with different mean diameters of 15–83 nm were synthesized by solution reduction process. The size of Ni nanoparticles can be controlled by varying the concentration of NiCl2·6H2O and synthesis temperature. The samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), infrared spectroscopy (IR) and X-ray photoelectron spectroscopy (XPS). Results show that the synthesized particles are single-phased Ni with a face-centered cubic crystal structure. Magnetic measurements indicate that Ni nanoparticles are ferromagnetic. The lattice constants and coercivities of the samples are size-dependent.