Wurtzite Type SiC Whiskers Obtained by Sublimation Method and the Thermal Stability of the Basic Polytypes of SiC

Abstract

By the sublimation method, 2H-type SiC whiskers were obtained. From the experimental results and the results from the heating experiments of powdered mixture of high pure silicon and graphite, the thermal stability of the basic polytypes of SiC were discussed. The conclusions are summarized as follows;1) The β-SiC grow in the whole range of temperature under the condition of high supersaturation.2) Initial phase appeared from β-SiC with heatings is mainly 6H above 1600°C and mainly 4H or 2H below 1400°C.3) Each basic polytypes of SiC, 2H, 3C, 4H, and 6H is stable in the range of temperature, below 1400°C, 1400°-1600°C, 1600°-2100°C, and above 2100°C respectively. The 15R-type is unstable form in the whole range of temperature.