SiC–SiOx heterojunctions in nanowires

Abstract

Novel 2-D nanoscale SiC networks have been generated by heating SiC–Fe–Co mixtures under a CO atmosphere. Examination of the products by EDX and HRTEM showed that most of the nanowires consist of β-SiC elongated single crystals, wrapped in amorphous SiO_x sheaths. Intriguing crystalline features and defects associated with SiC nanowires were observed. We believe that a binary Fe–Co catalyst is responsible for the SiC network: Fe catalyses the formation of the SiC inner cores and Co the SiO_x (x = 1–2) outer shell. A two-step growth mechanism, involving a vapour–liquid–solid (V–L–S) step, is thought to account for SiC nanowire creation.