Mechanical and electronic properties of hard rhenium diboride of low elastic compressibility studied by first-principles calculation

The mechanical and electronic properties of hcp-ReB2 are calculated by a first-principles approach. The calculated extreme equilibrium mechanical properties are consistent with the available experimental and theoretical data. The calculated elastic moduli suggest that hcp-ReB2 has a low compressibility and is most likely an intrinsically brittle material, but its relatively low ideal shear strength, as compared with c-BN, indicates that it is not intrinsically stronger/harder than c-BN. Based on the calculated electronic density of states and valence charge density distribution, the bonding nature of hcp-ReB2 is examined to obtain a deeper insight into the physical origin of the mechanical properties. (c) 2007 American Institute of Physics.