DESIGNING SUPERHARD MATERIALS BY INCORPORATING BORON INTO HEAVY TRANSITION METALS

First-principles calculations on the incompressibility, elasticity and hardness of the Os, OsB(2), Re, and ReB(2) materials have systematically been performed by the plane-wave basis pseudopotential method. Transition metals Os and re, which have high bulk modulus but low hardness, can be converted into hard materials by combining them with small B atoms. Moreover, electronic and structural mechanisms of ReB(2) and OsB(2) are analyzed in detail and compared. It is shown that incorporating small B atoms into heavy transition metals should be a valid pathway to obtain new superhard materials.