Core-shell structure powder for SiC single crystal growth and preparation process of core-shell structure powder

The invention provides core-shell structure powder for SiC single crystal growth and a preparation process of the core-shell structure powder. The powder comprises a core, a middle layer and a shell, wherein the core is SiC-Si mixed powder of large-particle-size Si particles and small-particle-size SiC particles, the middle layer is large-particle-size SiC powder, the shell is carbon-rich SiC powder, and the carbon-rich SiC powder of the shell is obtained by heating SiC powder in a graphite crucible at a temperature of 2000-2400 DEG C. According to the invention, when a silicon carbide single crystal is prepared by adopting a physical vapor transport method, the core-shell structure powder disclosed by the invention can realize effective isolation of different powder silicon carbide particles, and can realize reasonable adjustment of carbon and silicon components in different heating sublimation stages, so that the problems of sintering and non-uniform heating in the heating sublimation process of the existing silicon carbide powder are effectively improved, and finally, high-quality silicon carbide single crystals can be obtained.