Abstract:
Several methods have been employed to synthesize SiC nanowires. The methods include heating silica gel or fumed silica with activated carbon in a reducing atmosphere, the carbon particles being produced in situ in one of the methods. The simplest method to obtain beta-SiC nanowires involves heating silica gel with activated carbon at 1360 degreesC in H-2 or NH3. The same reaction, if carried out in the presence of catalytic iron particles, at 1200 degreesC gives alpha-Si3N4 nanowires and Si2N2O nanowires at 1100 degreesC. Another method to obtain Si3N4 nanowires is to heat multi-walled carbon nanotubes with silica gel at 1360 degreesC in an atmosphere of NH3. In the presence of catalytic Fe particles, this method yields alpha-Si3N4 nanowires in pure form.
