First principles calculation on electronic structure, chemical bonding, elastic and optical properties of novel tungsten triboride

The electronic structures, chemical bonding, elastic and optical properties of the novel hP24 phase WB3 were investigated by using density-functional theory (DFT) within generalized gradient approximation (GGA). The calculated energy band structures show that the hP24 phase WB3 is metallic material. The density of state (DOS) and the partial density of state (PDOS) calculations show that the DOS near the Fermi level is mainly from the W 5d and B 2p states. Population analysis suggests that the chemical bonding in hP24-WB3 has predominantly covalent characteristics with mixed covalent-ionic characteristics. Basic physical properties, such as lattice constant, bulk modulus, shear modulus and elastic constants Cij were calculated. The elastic modulus E and Poisson ratio ν were also predicted. The results show that hP24-WB3 phase is mechanically stable and behaves in a brittle manner. Detailed analysis of all optical functions reveals that WB3 is a better dielectric material, and reflectivity spectra show that WB3 can be promised as good coating material in the energy regions of 8.5–11.4 eV and 14.5–15.5 eV.