A HIGH-TEMPERATURE STUDY OF THE REACTION SIH4-REVERSIBLE-ARROW-SIH3+H-2(H)

The reaction of silane with H atoms SiH4+H reversible arrow(ks)SiH(3)H-2 was studied behind reflected shock waves at temperatures between 9 98 K and 1273 K and pressures around 1.5 bar. The thermal decompositio n of a few ppm ethyl iodide (C2H5I) was used as a well known H-atom so urce. The atomic resonance absorption spectroscopy (ARAS) was applied for time resolved and simultaneous measurements of H-and Si-atom conce ntrations. The presence of an excess of SiH4 causes a fast consumption of H atoms according to reaction (R5). The signals obtained were kine tically evaluated by computer simulations based on a simplified reacti on mechanism. The rate coefficient for reaction (R5) was found to be: k(5)=7.8x10(14) exp (-2260/T) cm(3) mol(-1) s(-1).