Structural, elastic, electronic and dynamical properties of OsB and ReB: Density functional calculations

The low coordination number of nitrogen in hard tungsten nitrides: a first-principles study

“…33 Besides, there are also nearly flats bands along Г-K-H-A and Г-M-L-H directions, which signal strong stiffness and 25 high bulk modulus. 33,34 As to the crystal structures, we find that, except for WN 2 , all W-N phases merge isolated N atoms occupying interstitial sites of W sublattice (Fig. 2).…”

Elastic and Dynamical Properties of YB 4 : First-Principles Study

“…For example, pure osmium (Os) has a bulk modulus of 410 GPa, which is slightly lower than the value 442 GPa of diamond, while hardness of pure Os is only one thirtieth of that of diamond. [3] An effective strategy of improving the hardness of a transition metal is to insert light covalent elements (such as, B, C, N, and O) into a pure metal lattice by enhancing its shear modulus, [4,5] as reported in ReB 2 , [2,3] WB 4 , [6] ReN 2 , [7] and ReO 2 . [8] Although the mechanical and electronic properties have been widely studied for 3𝑑 or 4𝑑 transition metal borides, studies for yttrium borides, in particular for YB 4 , are few.…”

Lattice dynamical and thermodynamical properties of ReB 2 , RuB 2 , and OsB 2 compounds in the ReB 2 structure

“…1, there are nearly flat bands along Γ -M and Γ -A directions, which signals strong stiffness, bringing about a very high bulk modulus for these compounds. [44] As shown in Fig. 1, there are a few optical phonon modes at the bottom of the optical phonon branch moving down toward the acoustic region along the Γ -M -A directions.…”

“…A similar characteristic of the highest frequency is not observed at the Γ point in many transition metal carbides, nitrides, and borides. [44,45] This characteristic can be explained by differences in their total and reduced masses as well as their lattice constants. The magnitude of the band gap follows the order of OsB 2 (6.046 THz) → ReB 2 (4.833 THz) → RuB 2 (3.217 THz).…”