DESIGNING SUPERHARD MATERIALS BY INCORPORATING BORON INTO HEAVY TRANSITION METALS

摘要

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 mod_ulus 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.