Formation of Copper-Nickel Alloy from Their Oxide Mixtures Through Reduction by Low-Temperature Hydrogen Plasma

Abstract

The paper presents experimental results of a new method of production of nanoparticles of copper-nickel alloys from the reduction of the mixture of cupric oxide (CuO) and nickel oxide (NiO) by low-temperature hydrogen plasma in a microwave assisted hydrogen plasma set-up. The microwave power and hydrogen flow-rate used for the current investigation are 750 W and 2.5 x 10(-6) m(3) s(-1) respectively. The addition of NiO-CuO, in proportion to result in alloys of 90Cu:10Ni and 70Cu:30Ni, not only removed the induction period from the kinetic plot of CuO reduction but also, improved the reduction rate of CuO. The XRD analysis of the product exhibited a single-phase peak with a d-spacing lying between Cu and Ni, which satisfies the Vergard's law, indicating the Cu-Ni alloy formation. The lattice parameter decreases from 3.6221 (90Cu:10Ni) to 3.595 C (70Cu:30Ni), due to the smaller atomic radius of Ni (0.1246 nm) than that of Cu (0.1278 nm). The crystallite size, calculated by applying Scherrer's formula, in both cases is found to be 31.7 nm.