First-principles study of low compressibility osmium borides

Abstract

Using first-principles total energy calculations we investigate the structural,elastic, and electronic properties of Os B 2 and OsB, respectively. The calculated equilibrium structural parameters of Os B 2 are in agreement with the available experimental results. The calculations indicate that OsB in tungsten carbide is more energetically stable under the ambient condition than the metastable cesium chloride phase of OsB. Results of bulk modulus show that they are potential low compressible materials. The hardness of Os B 2 is estimated by employing a semiempirical theory. The results indicate that Os B 2 is an ultraincompressible material, but not a superhard material. The method designing superhard materials is different from one creating ultraincompressible materials.