A novel laser-liquid-solid interaction technique for synthesis of silver, nickel and immiscible silver-nickel alloys from liquid precursors

Silver, nickel, nickel oxide and silver-nickel alloys have been produced fr om their inexpensive liquid precursors using CO2 and Nd-YAG lasers. Ethylen e glycol, diethylene glycol and 2-ethoxyethanol were used as reductants in the synthesis reactions. Spherical and faceted silver particles of high pur ity were formed by laser interaction between the precursor solution and a r otating substrate, while porous dual phase nickel and nickel oxide particle s were produced when nickel nitrate was used as a precursor. The compositio n and morphology of the alloy particles was dependent on laser parameters a nd chemical composition of the precursor solution. The product composition was dependent only upon the chemistry of the precursors used. The mean part icle size was dependent upon the temperature generated by irradition and th e duration of exposure to the laser beam. The synthesis of nano-particles a nd metastable alloys is proposed to occur primarily at the laser-liquid-sol id interface by a nucleation and growth mechanism. (C) 2000 Kluwer Academic Publishers.