Cubic SiC nanowire synthesis by DC arc discharge under ambient air conditions

Abstract

Silicon carbide (SiC) is a widely used material characterized by unique physical and chemical properties. In the paper, cubic silicon carbide nanowires are synthesized via the non-vacuum DC (direct current) arc discharge method. DC arc is generated between the graphite rod and the graphite crucible under ambient air conditions without any vacuum or applying special defenses to the used atmosphere equipment. According to experimental data, the percentage of silicon carbide of the total product in interval from 70 A to 100 A increases from 3.9% up to 26.7% (mass), and in interval from 130 A to 200 A of arc discharge current decreases from 26.1% down to 19.9% (mass). The silicon carbide wires are characterized by the typical core-shell SiC–SiOx structure. It is possible to control the phase composition and increase the yield of SiC by changing the arc discharge current amplitude. The optimal synthesis parameters using the DC source with the maximum current of 200 A are a current of 200 A, synthesis time of 12 s and a silicon fraction in the initial mixture not more than 25% (mass) to completely process the initial silicon into its carbide.