Computer simulations of 3C-SiC under hydrostatic and non-hydrostatic stresses

Area of Science:

• Materials Science
• Solid-State Physics
• Computational Chemistry

Background:

• Silicon carbide (SiC) is a crucial material with diverse applications.
• Understanding its mechanical and electronic properties under stress is vital for advanced technologies.

Purpose of the Study:

• To investigate the response of 3C-SiC to hydrostatic and anisotropic stress conditions.
• To analyze the changes in chemical bonding and electronic structure under pressure.

Main Methods:

• First principles calculations were employed to simulate stress conditions.
• Topological analysis of chemical bonding was used to interpret structural changes.

Main Results:

• 3C-SiC exhibits low compressibility and high structural stability under hydrostatic pressure.
• Uniaxial [001] stress leads to a significant drop in the c/a ratio.
• A band gap closure and emergence of a metallic state were observed around 40 GPa under uniaxial stress.

Conclusions:

• Non-covalent interactions increase at high pressures, while the covalent Si-C bond network remains largely unchanged.
• The observed metallization under uniaxial stress is linked to specific electron localization patterns around bonded units.