Phase equilibrium in the formation of silicon carbide by topochemical conversion of silicon

Abstract

Methods of linear algebra were used to find a basis of independent chemical reactions in the topochemical conversion of silicon into silicon carbide by the reaction with carbon monoxide. The pressure–flow phase diagram was calculated from this basis, describing the composition of the solid phase for a particular design of vacuum furnace. It was demonstrated that to grow pure silicon carbide, it is necessary to ensure the pressure of carbon monoxide less than a certain value and its flow more than a certain value, depending on the temperature of the process. The elastic fields around vacancies formed were considered for the first time in calculating the topochemical reaction. It was shown that the anisotropy of these fields in a cubic crystal increases the constant of the main reaction approximately fourfold.