Comparison of the SiH 4C 2H 4 and SiH 2Cl 2C 2H 4 systems during the synthesis of silicon carbide ultrafine particles by laser-induced gas-phase reaction

Abstract

The synthesis conditions of SiC ultrafine particles from SiH 4 and C 2H 4 using a CO 2 laser were studied and a comparison was made between SiH 4C 2H 4 and SiH 2Cl 2C 2H 4 systems. Ultrafine SiC particles were synthesized by irradiating a SiH 4 and C 2H 4 gas mixture with a CO 2 laser at atmospheric pressure. SiC particles were obtained at a laser power of more than 0·92 kW/cm 2. The behavior of the reaction flame temperature and the extent of the laser light absorption by SiH 4C 2H 4 was different from that of SiH 2Cl 2C 2H 4, although an abrupt temperature increase was observed in both cases. In the case of SiH 4C 2H 4 an abrupt increase in the laser light absorption was not observed, whilst it was observed in the case of SiH 2Cl 2C 2H 4. This difference resulted from the difference in liability to form solid carbon particles.