Thermal expansion of the cubic (3C) polytype of SiC

Abstract

Thermal expansion of the cubic beta or (3C) polytype of SiC was measured from 20 to 1000° C by the X-ray diffraction technique. Over that temperature range, the coefficient of thermal expansion can be expressed as the second order polynominal: α₁₁=3.19×10⁻⁶+ 3.60×10⁻⁹ T−1.68×10⁻¹² T ² (1/° C). It increases continuously from about 3.2×10⁻⁶/° C at room temperature to 5.1×10⁻⁶/° C at 1000° C, with an average value of 4.45 × 10⁻⁶/° C between room temperature and 1000° C. This trend is compared with other published results and is discussed in terms of structural contributions to the thermal expansion.