Predicting structural, elastic, and optoelectronic properties of oxide perovskites HfXO3 (X =Be, Mg) employing the DFT approach

Abstract

This study conducts a comprehensive exploration of the structural, electronic, elastic, and optical properties of HfXO3 (X=Be, Mg) perovskite compounds, employing density functional theory (DFT) within the WIEN2k code. Employing the Birch Murnaghan fitting technique, our structural evaluation establishes the structural stability of these materials, with optimized lattice constants underscoring their stability at specific values. By harnessing the capabilities of the IRelast software, we have determined elastic constants and characterized the anisotropic tendencies, disclosing that both compounds exhibit a pronounced degree of anisotropy. Moreover, an in-depth investigation into electronic attributes, facilitated by the modified Becke–Johnson potential, uncovers these materials as indirect narrow band gap semiconductors, with calculated band gaps of 1.14 eV for HfBeO3 and 0.8 eV for HfMgO3 serving as vital indicators of their electronic character. Furthermore, we delve into the optical traits of these materials, revealing their photon transparency within the energy spectrum of 0 eV to 15 eV. These key optical properties encompass dielectric functions, refractive index, optical conductivity, absorption coefficient, extinction coefficient, energy loss function, and reflectivity. This comprehensive exploration offers a holistic understanding of the optical behaviors exhibited by these materials. By skillfully combining structural, electronic, elastic, and optical analyses, this study significantly contributes to the comprehension of HfXO3 (X=Be, Mg) perovskites, forging a path for their potential applications and serving as a foundation for future research endeavors.