Synthesis and growth mechanism of SiC/SiO₂ nanochains heterostructure by catalyst-free chemical vapor deposition

The SiC/SiO₂ nanochains heterostructure with double amorphous layers was successfully synthesized by a catalyst-free chemical vapor deposition process at 1280°C. The SiC/SiO₂ nanochains experience an apparent regular periodic structure, whose SiO₂ beads with diameters of about 160 nm are positioned on the SiC strings beside one another. Their growth mechanism could be mainly ascribed to Rayleigh instability and vapor-solid mechanism. The double layers structure of amorphous silica on the surface of the strings results from the different silica deposition stages. SiC nanowires with diameters of 20-50 nm were also found accompanied with the SiC/SiO₂ nanochains and not changed into the chains-shaped morphology because of their small diameters and much higher additive surface pressure of bending silica melt layer on the nanowires.