Nanometric powder of stoichiometric silicon carbide produced in square-wave modulated RF glow discharges

✍ Scribed by G Viera; S.N Sharma; J.L újar; R.Q Zhang; J Costa; E Bertran

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 237 KB
• Volume: 52
• Category: Article
• ISSN: 0042-207X
• DOI: 10.1016/s0042-207x(98)00203-6

✦ Synopsis

SiC nanometric powder has been obtained in square-wave modulated radiofrequency glow discharges from CH 4 and SiH 4 gas mixtures. Chemical and structural characterization revealed that the as-deposited SiC:H powder underwent spontaneous oxidation when exposed to atmosphere. To stabilise the powder chemically, we carried out a thermal treatment under vacuum (10 À 4 Pa) consisting of heating to 8008C (208C/min). The eects on the structure of the powder were examined by FTIR, EA, XPS and from optical transmittance measurements. They can be summarized as follows: dehydrogenation of the powder that induces the formation of a SiC carbidic network and chemical stability under atmospheric conditions, further con®rmed by exposure to air for more than 6 months. In addition, TEM images showed that the annealed powder presented a short-range order in b-SiC units, but there was no evidence of size changes due to sinterization or compactaction phenomena.