Mechanical, Electronic, and Optical Properties of β-B6O: First-Principles Calculations

The mechanical, electronic, and optical properties of beta-B6O are calculated by first-principles. The structural optimization and all properties are calculated by the method of generalized gradient approximation - Perdew, Burke and Ernzerhof (PBE). The hardness of beta-B6O is 39 GPa under a pressure of 0 GPa, which indicates that it belongs to a hard material. The band gap is indirect with a value of 1.836 eV, showing that beta-B6O is a semiconductor. The research of the electron localization function shows that the bonds of beta-B6O are covalent bonds, which can increase the stability of the compound. The phonon dispersion curves present the dynamical stability of beta-B6O under pressures of 0 and 50 GPa. The optical properties of beta-B6O are also calculated. In the energy range from 0 to 18 eV, beta-B6O presents high reflectivity; it has a strong absorption in the energy range from 3 to 18 eV. The refractive index results show that light propagates through the beta-B6O in a difficult manner in the energy range from 6.9 to 16.5 eV. In addition, the energy of the plasma frequency for beta-B6O is 16.6 eV and the peak value of the loss function is 13.6. These properties provide the basis for the development and application of beta-B6O.