Plasma Chemistry and Plasma Processing, Vol.39, No.4, 1071-1086, 2019
Formation of CuCo Alloy From Their Oxide Mixtures Through Reduction by Low-Temperature Hydrogen Plasma
Experimental results of a new method of production of CuCo alloy of composition 95Cu-5Co from the reduction of the mixture of cupric oxide (CuO) and cobalt oxide (Co3O4) is presented. It uses low-temperature hydrogen plasma which in turn is created in a microwave assisted plasma set-up. The microwave power and hydrogen flow-rate used in this investigation are 750W and 2.5x10(-6) m(3) s(-1) respectively. Co3O4 reduced faster than CuO. The reduced molar volume of Co3O4 provided more space for hydrogen penetration. The addition of Co3O4 to CuO, not only removed the induction period from the kinetic plot of CuO reduction but also, improved the reduction rate of CuO. The kinetic data fits the Avrami model of nucleation and growth with a model parameter closer to 1.5. The alloy showed positive deviation from Vegard's law. The crystallite size, calculated by applying Scherrer's formula lies in the range of 21.5-30.7nm.
Keywords:Nanoparticles;CuCo alloy;Giant magnetoresistance;Low-temperature hydrogen plasma;Vegard's law;Reduction of metal oxides