Cubic $γ-Be3N2$⁠: A superhard semiconductor predicted from first principles Available to Purchase

The authors predict a superhard semiconductor phase of $Be3N2$ with cubic structure using first-principles calculations. The structural, mechanical, electronic, and optical properties of the $Be3N2$ have been investigated. Results indicate that the predicted $Be3N2$ phase is a wide gap semiconductor with a direct band gap of about $2.51eV$⁠. The calculated hardness of cubic $γ-Be3N2$ based on Mulliken overlap population analysis in first-principles technique approaches those of $B4C$ and $B6O$⁠. The higher mechanical property can be attributed to the existence of strong Be–N–Be covalent bond chains in the cubic structure. The obtained static dielectric constant of $Be3N2$ $(4.6eV)$ is close to the spinel structure of $Si3N4$ $(4.7eV)$⁠.