Influence of extended defects on melting behavior of 3C-SiC by molecular dynamics simulations

The effect of typical extended defects in cubic Si carbide (3C-SiC), namely Shockley partial dislocations and their complexes, on the melting behavior of this material is studied by molecular dynamics simulations. The obtained results evidence a compelling link between the presence of extended defects and the reduction in the 3C-SiC melting temperature. The melting temperature is found to decrease with the concentration of single partial dislocations with the tendency of saturation at ~ 165 K below the respective value for the defect-free material. In their turn, extrinsic partial dislocations reduce the 3C-SiC melting temperature by only about 50 K independently of the concentration, and the effect of triple dislocation complexes is at all negligible. The mechanism of the observed phenomena is discussed in terms of the strain and excess elastic energy introduced by the defects under study. The obtained results have implications for development of 3C-SiC based devices operating at extreme temperatures, from aerospace electronics to thermal protection systems.