Magnetic-field-assisted synthesis of Ni nanostructures: Selective control of particle shape

Metallic nickel particles have been selectively synthesized via chemical reduction using a static magnetic field. Our results demonstrated that both reduction temperature and magnetic-field strength were the crucial factors in determining the final particle shapes. Upon subjecting a 0.02 T magnetic field, the particles change from sea urchin-like, through spherical, to one-dimensional (1D) in shape with decreasing the reduction temperature. In the synthesis of 1D structure, sphere-chains with fluctuant diameter are assembled under weaker magnetic field while relatively smooth nanowires are formed under stronger one. Thermal analysis of the particles was also investigated.