Abstract: Ultrafine nickel powders were prepared fromnickel chloride reduced by hydrazine in aqueous solution of sodium dodecyl sulfate (SDS)-polyvinylpyrrolidone (PVP). SEMresults showed that the reduced products were sphere with special needle-like morphology. XRD displayed that the spherical ultrafine nickel powders were self-assembled into by the primary pure crystalline nanonickel of face centric structural (fcc) with the mean crystal size about 10 nm, and grown preferentially along (111) lattice plane. The process that the primary pure crystalline nanonickel self-assembled into the ultrafine nickel powders in virtue of the coupling of PVP chain was clearly observed by TEM. The composition of SDS-PVP mixing system had great influence on the size and shape of ultrafine nickel powders. At a certain concentration, the sizes of the primary pure crystalline nanonickel and the secondary ultrafine nickel powders showed that a decreased trend with increasing the concentration of SDS or PVP revealed a promising possibility of a size and morphology controllable production of the ultrafine nickel particles by adjusting the composition of SDS and PVP.

Key words: Ultrafine nickel powder, Preparation, Sodiumdodecyl sulfate, Polyvinylpyrrolidone