Mechanical and Electronic Properties of P4₂/mnm Silicon Carbides

Abstract

Abstract Two new phases of Si 8 C 4 and Si 4 C 8 with the P4 2 /mnm symmetry are proposed. Using first principles calculations based on density functional theory, the structural, elastic, and electronic properties of Si 8 C 4 and Si 4 C 8 are studied systematically. Both Si 8 C 4 and Si 4 C 8 are proved to be mechanically and dynamically stable. The elastic anisotropies of Si 8 C 4 and Si 4 C 8 are studied in detail. Electronic structure calculations show that Si 8 C 4 and Si 4 C 8 are indirect semiconductors with the band gap of 0.74 and 0.15 eV, respectively.