alpha-Si3N4 nanowires, beta-SiC nanowires and SiO2 amorphous nanowires are synthesized via the direct current arc discharge method with a mixture of silicon, activated carbon and silicon dioxide as the precursor. The alpha-Si3N4 nanowires, beta-SiC nanowires and SiO2 amorphous nanowires are about 50-200 nm in stem diameter and 10-100 mu m in length. alpha-Si3N4 nanowires and beta-SiC nanowires consist of a solid single-crystalline core along the [0 0 1] and [1 1 1] directions, respectively, wrapped within an amorphous SiOx layer. The direct current arc plasma-assisted self-catalytic vapor-solid and/or vapor-liquid-solid (VLS) growth processes are proposed as the growth mechanism of the nanowires. (C) 2010 Elsevier B.V. All rights reserved.