High yield solvothermal synthesis of Ni nanoparticles: structural, microstructural, and magnetic properties

Pure nickel nanoparticles have been synthesized via easy solvothermal route at low temperature, with a high yield of 97%, in the absence of any surfactant, ligand, or external magnetic field. The samples were analyzed through FE-SEM/EDS, XRD, and magnetic measurements. The size of nickel nanoparticles was monitored by adjusting the annealing temperature. The lowest particle size (60 nm) was obtained for an annealing temperature of 130 degrees C. The XRD patterns exhibited an FCC crystal structure with lattice parameter value close to that of pure Ni (a = 3.525 A). The average anisotropic crystallite size was around 17 nm. The samples showed a soft ferromagnetic behavior with saturation magnetization values lower than pure bulk Ni. The coercivity was between 103 and 218 Oe. The variation of the magnetic parameters was correlated to particles size and morphology of the synthesized powders.