High-temperature stability of copper nanoparticles through Cu@Ag nanostructures

Copper nanoparticles are promising materials for the development of low-cost, low-temperature processable materials for the interconnection technology. Owing to its low price, copper is expected to replace silver in many applications; however, it suffers from its proneness to oxidation, in particular for nanoparticles due to the high surface-to-volume ratio. In this study, we report the synthesis and the characterization by SEM, TEM-EDS, XRD, and TGA of several Cu-based core-shell nanoparticles. We show that their thermal stability in air towards oxidation can be highly enhanced thanks to a simple core–shell fabrication process. Best results were obtained with thermally post-treated 6-nm-silver-thick shells, which allow to improve the oxidation onset temperature up to 206 °C. [Figure not available: see fulltext.].