Premixed silaneoxygennitrogen flames

Tokuhashi, Kazuaki; Horiguchi, S.; Urano, Youkichi; Iwasaka, Masaji; Ohtani, Hideo; Kondô, Shigeo

doi:10.1016/0010-2180(90)90076-4

Cited by 39 publications

(16 citation statements)

References 7 publications

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“…Hence, a flame temperature of about 1000°K or more should be required to allow silane decomposition to contribute to flame propagation. From [48] have shown that the burning velocity attains about 55 cm/s at 2mol% silane (roughly 1 0 c d s faster than optimum methane-air). The data suggest that by 2.2-2.3 mol% silane the burning velocity will attain about 80 cm/s, which approximates to that of optimum ethylene-air.…”

Section: (F) Effect Of Hydrogen Diluent Flammability Limits For Silanmentioning

confidence: 98%

“…The test mixtures were very lean, since the stoichiometric concen-tration of silane in air is 9.51 mol%. The schlieren burner method used by Tokuhashi, et al [48] could be used down to a silane concentration of 1.6 mol%, at which the burning velocity was about 20cm/s and the flame temperature (measured with a fine thermocouple) was about 800°K. Below 1.6 mol% silane a flame could not be maintained in silane-nitrogen-oxygen mixtures, regardless of the oxygen concentration.…”

Section: (F) Effect Of Hydrogen Diluent Flammability Limits For Silanmentioning

confidence: 99%

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Combustion hazards of silane and its chlorides

Britton¹

1990

Plant/Oper. Prog.

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This paper addresses the unusual combustion hazards of silane and its chlorides, comprising the homologous chlorosilane series SiHnCl4‐n. The literature on silane is briefly reviewed and new experimental data presented showing the effects of sudden releases into free air. New data are presented for ignition sensitivities and deflagration rates of chlorosilane mixtures with air. Specific hazardous reactions of this group of materials are described and contrasted with those of the analogous alkanes. Mechanisms for flame acceleration and transition to detonation are discussed.

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Section: (F) Effect Of Hydrogen Diluent Flammability Limits For Silanmentioning

confidence: 98%

Section: (F) Effect Of Hydrogen Diluent Flammability Limits For Silanmentioning

confidence: 99%

Combustion hazards of silane and its chlorides

Britton¹

1990

Plant/Oper. Prog.

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“…Although the last parameter was mentioned previously, 40 the main reason for the low growth rate of silicon nitride is attributed to the small reaction rate coefficients of N and NH 2 radicals with SiH 4 ͑Table I͒ as compared to atomic oxygen either in its fundamental or its excited state. 3,37,38,[41][42][43] In the dual-plasma regime, stoichiometric films with kр10 Ϫ3 at 3.8 eV, were grown using rather high values of the flow-rate ratios R ͑relative to silane͒, e.g., Rу10 with NH 3 and Rу20 with N 2 . The higher refractive index n ͑3.8 eV͒ found for stoichiometric nitrides obtained with N 2 gas ͑2.00͒ as compared to NH 3 ͑1.93͒ is attributed to a higher film density.…”

Section: Amorphous Silicon Nitrides A-sin Y :Hmentioning

confidence: 99%

Dual-plasma reactor for low temperature deposition of wide band-gap silicon alloys

Etemadi

Godet

Perrin

et al. 1997

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

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A dual-plasma [surface wave-coupled microwave (MW) at 2.45 GHz and capacitively coupled radio frequency (rf) at 13.56 MHz] reactor called MORFAX was developed for the deposition of amorphous wide band-gap alloys (a-SiOx:H, a-SiNy:H) at high growth rates and at low temperatures compatible with usual polymer substrates. These optical thin films may be used as components of multilayer coatings, such as index gradient devices or transparent interferential filters, to protect optical polymers. The dual-plasma MORFAX reactor was designed to provide three advantages: a high reactive species density (MW), a chemical selectivity due to the separation of the MW plasma and the rf plasma regions, and a variable ion bombardment energy due to the rf plasma dc polarization. Using O2, NH3, or N2 gases diluted in He–Ar mixtures in the microwave plasma while silane was injected in the postdischarge region, we have obtained the following information. (i) Optical emission spectroscopy shows the changes in the electron energy distribution function for single- and dual-plasma modes as a function of the (He–Ar) mixture composition, that in turn provides a means to control the reactive gas processes. (ii) In the single MW mode, the decomposition of O2 (diluted in He–Ar) is very efficient, producing an atomic oxygen density of [O]≈1014cm−3; due to low wall recombination, a high density of atomic O is transported in the flowing afterglow where silane is very strongly decomposed by O atoms. (iii) In the dual-plasma mode, atomic oxygen produced in the MW plasma and electrons due to the rf plasma both participate in the silane decomposition. Cooperative effects between the MW postdischarge and the rf plasma were observed, in particular on the deposition rate of silicon oxide films. (iv) As compared to oxide growth rates (up to 5 nm s−1 limited by the silane depletion), the lower growth rate of silicon nitride films is attributed to the small reactive dissociation coefficient of SiH4 by N and NH2 radicals. (v) In situ and ex situvibrational spectroscopy and spectroscopic ellipsometry show that the ion energy can be effectively used to increase the density of the oxide films. At 70 °C, good control of the stoichiometry and porosity of a-SiOx:H films was obtained over the full composition range (0⩽x⩽2.2). Water molecules are reversibly adsorbed upon exposure of the porous oxide films to the ambient and are desorbed under vacuum at room temperature.

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“…Pressure traces typical of detonation were observed for X N2 ≤0.62, at P 1 =101 kPa and T 1 =283 K. Whereas many laminar flame speed studies have been performed for hydrocarbon-based mixtures [10], very few have been made for silicon-containing compounds. Despite the pyrophoric nature of silane, Tokuhashi et al [11] were able to measure the burning velocity of various SiH 4 -O 2 -N 2 mixtures using a specially designed burner. They reported a burning velocity of 55 cm/s for a mixture of 2% of SiH 4 in air.…”

Section: Introductionmentioning

confidence: 99%

Combustion of silane-nitrous oxide-argon mixtures: Analysis of laminar flame propagation and condensed products

Mével

Chatelain

et al. 2021

Proceedings of the Combustion Institute

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The laminar burning rate, the explosion peak pressure, and the pressure rise coefficient have been measured for the first time for silane-nitrous oxide-argon mixtures using the spherically expanding flame technique in a constant volume combustion chamber. For these three parameters, the values obtained were higher than for hydrogen-nitrous oxide-argon and typical hydrocarbon-based mixtures. A maximum burning rate of 1800 g/m 2 s was measured at 101 kPa, whereas under similar conditions, a maximum burning rate around 950 g/m 2 s has been reported for hydrogen-nitrous oxide-argon mixtures. To better understand the chemical dynamics of flames propagating in SiH 4 -N 2 O-Ar mixtures, a detailed reaction model from the literature was improved using collision limit violation analysis and updated thermodynamic properties calculated with a high-level ab initio approach. The reaction model predicts the burning rate within 14% on average but demonstrates error close to 50% for the richest mixtures. The chemistry of the H-O-N system is important under all the conditions presently studied. The chemistry of the Si-H-O-N system demonstrates an increasing importance under rich conditions. In particular, the reactions (i) forming SiO x (s); (ii) describing the interaction of Si-species with N 2 O; and (iii) involving silicon hydrides, have an important role for the heat release dynamics. The condensed combustion products formed in the silane-nitrous oxide-argon flames were sampled and characterized using electron micrograph, electronic diffraction, energy-dispersive spectroscopy, and X-ray powder diffraction. For all equivalence ratios, silica spherical particles with a mean diameter in the range 200-300 nm were observed. In addition, for mixtures with Φ≥2.2, silicon nanowires were formed. X-ray diffraction experiments showed that the silicon nanowires are composed of metal silicon characterized by a cubic structure (lattice parameter: a=5.425 Å) with the Fm-3m space group.

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Premixed silaneoxygennitrogen flames

Cited by 39 publications

References 7 publications

Combustion hazards of silane and its chlorides

Combustion hazards of silane and its chlorides

Dual-plasma reactor for low temperature deposition of wide band-gap silicon alloys

Combustion of silane-nitrous oxide-argon mixtures: Analysis of laminar flame propagation and condensed products

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