Monoclinic C12: A new superhard carbon allotrope

Superhard materials have always been the focus of scientific research. Based on crystal structure prediction technique along with first-principles calculations, a new superhard carbon structure C12 (space group: C2/m) was proposed. This C12 structure is composed of sp2-sp3 hybrid bonding network. Analyses of its mechanical properties show that the structure is mechanically stable and exhibits strong anisotropy. The dynamic stability of C12 at ambient pressure is confirmed by phonon spectra. The analysis of its electronic band structure reveals that C12 is a narrow bandgap semiconductor. Its hardness reaches approximately 67 GPa, which means C12 is a potential superhard semiconductor material. C12 is expected to be used in new semiconductors in the future.

Automated summary

Based on crystal structure prediction technique and first-principles calculations, a new superhard carbon structure C12 (space group: C2/m) with sp2-sp3 hybrid bonding network was proposed. Mechanical properties analysis demonstrates its mechanical stability and strong anisotropy. Phonon spectra confirm its dynamic stability at ambient pressure. Electronic band structure analysis reveals C12 as a narrow bandgap semiconductor with hardness of approximately 67 GPa, making it a potential superhard semiconductor material for future applications.