Production of Ag Nanopowders by Inert Gas Condensation and Evaluation of Their Properties


Abstract: In this study, silver nanopowders were produced by inert gas condensation (IGC) in a reduced helium atmosphere.Helium gas was used as both cooling agent and carrier gas for the nucleating metal particles.Silver melt was fed from a 1 mm wire and was evaporated from a tungsten boat at 1500^oC with the background of 20 mbar pressure.The particles were formed by homogeneous nucleation in the carrier cooling gas and grew in a coalescence mode.The particle shape, size and specific surface area of the powders as well as their suitability for electrical conductivity were investigated.Electrical conductivity of the particles was measured at ambient and elevated temperatures (90^oC).It was found that the final particles, about 75 nm in diameter, formed a highly porous aggregate with substantial sinter neck formation.

Keywords: Ag Nanoparticles, Inert gas condensation method, Particle structure, Electrical conductivity

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