The structural properties,mechanical behavior,and electronic structure of the newly developed diamondlike BC5 (d-BC5) was investigated using density functional theory (DFT) calculations.The results indicate that d-BC5 has great bulk modulus of 393 GPa,large shear modulus of 398 GPa,and high hardness of 62 Pa,and thus support the fact that d-BC5 is an ultra-incompressible and superhard material.Remarkably,the superhard d-BC5 exhibits metallic features.Furthermore,the trend that the mechanical behavior falls with the increase of boron content was revealed.The combination of huge stiffness,high hardness,and good metallicity makes series of diamondlike BCx (d-BCx) valid for wider applications in comparison with pure diamond.
