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

Metastable silver-nickel alloys have been synthesized by chemical wetness and laser-liquid-solid interaction techniques from nitrate and acetate precursors of silver and nickel. Ethylene glycol and 2-ethoxyethanol were used as reductants in the synthesis reactions. Rotating niobium substrates immersed in the liquid precursor were irradiated by a continuous wave CO₂ and Nd-YAG laser (λ = 1064 nm). The powders were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and high-resolution transmission electron microscopy (HRTEM). Two-phase alloys containing silver, nickel, and oxygen were fabricated, and the shape of the particles was found to be dependent on laser parameters and the chemical composition of the precursor solution. The synthesis mechanism of non-equilibrium Ag-Ni alloy nanoparticles has been proposed to occur primarily at the laser-liquid-solid interface by a nucleation and growth mechanism.