Decomposition reaction rate of BCl3–CH4–H2 in the gas phase

Abstract

temperature. The concentration, consistent with the thermodynamics computations, of the reactants achieves a constant of consuming completely with the extension of time. The concentrations of precuts BC and C also increase with increasing temperature, and the concentration of B is always larger than BC in the temperature range of 1200-1600 K. Thus, the rich boron product is easy to form and to deposit at higher temperatures. However, the difference in concentrations (logarithm values) between BC and B becomes smaller with the increasing temperature. This result is also consistent with the experimental conclusion of Ye et al. (Mater Rev 24:108, 2010). The logarithm of the decreasing rate for CH 4 and the reciprocal temperature have excellent linear relationship at 700-2000 K with a correlation coefficient of 0.9999. The slope of the line corresponds to an apparent activation energy 208.4 kJ mol −1 , which is comparable with the energy barrier (238.6 kJ mol −1 ) of the rate control reaction. The logarithm of the decreasing rate for BCl 3 and the reciprocal temperature also have an excellent linear relationship in two temperature ranges 700-1600 and 1700-2000 K, predicting that the reaction follows obviously two different kinetics mechanisms. The correspondence apparent activation energies are 201.7 and 378.3 kJ mol −1 , respectively.

Machine learning and a computational fluid dynamic approach to estimate phase composition of chemical vapor deposition boron carbide

“…Based on the most favorable reaction path previously proposed, Liu et al [28] studied the reaction rate of the BCl /CH 4 /H 2 gas-phase system. Their rate constants were calculated for temperatures within 200-2000 K and adopted G45-G58 [29]. Reinisch et al [30] reported a set of theoretical experiments of the gas-phase decomposition of boron trichloride in the presence of hydrogen radicals, and their reactions are also included (G59-G62 in Table 3).…”

Machine learning and a computational fluid dynamic approach to estimate phase composition of chemical vapor deposition boron carbide

“…Based on the most favorable reaction path previously proposed, Su et al studied the reaction rate of the BCl 3 /CH 4 /H 2 gas-phase system [25]. Their rate constants were calculated for temperatures within 200-2000 K and adopted here (G45-G58) [26]. Reinisch et al…”

Gas‐phase kinetic of boron carbide chemical vapor deposition using BCl3+CH4+H2 mixture

“…14 Besides, they also demonstrate that the BCl 3 +H→BHCl 2 +Cl addition-elimination path consumes BCl 3 much faster than the direct abstraction route (BCl 3 +H→BCl 2 +HCl) proposed by Harris et al 15 In a similar study, it has been observed that the boron carbide and carbon content in the film increases with increasing temperature in the range of 1200-1600 K, and the fraction of boron is always more significant than B 4 C. Thus, the boron-rich film is easily formed at elevated temperatures. 16 In general, the manual development of a detailed mechanism is tedious and time consuming, missing out on a few reactions. However, the automatic mechanism generator (computer code) can build a large model.…”