SiO2–C reaction occurs in a graphite electric resistance
furnace at very high temperature (from 1400 up to
2700 ℃), leading to polycrystalline SiC varying in
purity [3–5]. Depending on temperature, two main
phases are possible: α-SiC, having hexagonal crystal
structure, is the stable form at elevated temperature as
high as 1700 ℃; β-SiC, having cubic zinc-blende
structure, is formed at temperature below 1700 ℃.