Synthesis of metastable silver-nickel alloys by a novel laser-liquid-solidinteraction technique

Metastable silver-nickel alloys have been synthesized by chemical wetness a nd laser-liquid-solid interaction techniques from nitrate and acetate precu rsors of silver and nickel. Ethylene glycol and 2-ethoxyethanol were used a s reductants in the synthesis reactions. Rotating niobium substrates immers ed in the liquid precursor were irradiated by a continuos wave CO2 and Nd-Y AG laser (lambda = 1064 nm). The powders were characterized by x-ray diffra ction (XRD), scanning electron microscopy (SEM), energy dispersive spectros copy (EDS) and high-resolution transmission electron microscopy (HRTEM). Tw o-phase alloys containing silver, nickel, and oxygen were fabricated, and t he shape of the particles was found to be dependent on laser parameters and the chemical composition of the precursor solution. The synthesis mechanis m of non-equilibrium Ag-Ni alloy nanoparticles has been proposed to occur p rimarily at the laser-liquid-solid interface by a nucleation and growth mec hanism. (C) 2000 Kluwer Academic Publishers.