Preparation and characterization of Ni-Cu composite nanoparticles for conductive paints

Abstract

Ni and Cu are the two most promising alternatives to noble metals used in electrical conductive materials. However, Cu is susceptible to oxidation, while Ni exhibits poorer electrical conductivity. To solve this problem, Cu-Ni composite nanoparticles have been prepared in the present work by successive hydrazine reduction based on the different oxidation potential between Cu (II) and Ni (II). The as-prepared products were characterized by XRD, FE-SEM, EDS, and TG, and the electrical resistivity of which was measured by four-probe method. A formation process of the composite particles was proposed and demonstrated. The Cu-Ni composite nanoparticles have a uniform diameter of about 50nm, and exhibit higher oxidation temperature than Cu and lower electrical resistivity than Ni. This novel Ni-Cu structure and method might help solve the problems associated with the oxidation of Cu and the low electrical conductivity of Ni, which would further promote the application of base metal conductive powders.

Keywords

• metallic powders
• composite nanoparticles
• electrical conductivity
• oxidation resistance