Bimetallic NixAg100–x nanoparticles as fillers for electrically conductive polymer composites

Bimetallic nanoparticles based on nickel and silver with different compositions were synthesized by co-precipitation of Ag+ and Ni2+ ions with sodium hydroxide in ethylene glycol solutions, followed by reduction of the resulting suspension with hydrazine. It was established that the introduction of Ag+ promotes the formation of particles smaller than 100 nm compared to approximately 300 nm for Ni NPs. X-ray diffraction (XRD) analysis showed that the investigated samples were two-phase systems in which nickel and silver crystallize in a face-centered cubic lattice. No unidentified peaks were observed in the 2θ range of 10°–100°, indicating the absence of undesired products, namely metal oxides or hydroxides. The specific electrical conductivity of the NiхAg100–х powder layer exhibited a non-monotonic dependence on the Ag content and reached 3570 S/m for Ni91Ag9. The obtained NiхAg100–х bimetallic nanoparticles were studied as conductive fillers for conductive polymer composites. The electrical conductivity of thin NiхAg100–х-based nanocomposites films was found to be relatively high at a low filler content (10 vol.%), reaching values above 220 S/m.