N2CO: A potential superhard material predicted by the first-principles calculations

Using the first-principles calculations, we have predicted the mechanical and thermal properties of N2CO, which belongs to the tetragonal structure (space group P4(3)) with a = 5.18 angstrom, c = 3.99 angstrom and the c/a = 0.77. The tetragonal phase N2CO is thermodynamically, mechanically and dynamically stable, as verified by the cohesive energy, elastic constants and phonon dispersion. Further research show that N2CO has brittleness (B/G = 1.22), high Vickers hardness (47 GPa) and high Debye temperature (1383 K). The results show that the tetragonal N2CO can potentially be used as a superhard material.