Density functional theory analysis of novel ZrO2 polymorphs: Unveiling structural stability, electronic structure, vibrational and optical properties

Abstract

The importance of advanced materials like zirconium dioxide (ZrO₂) in diverse medical, industrial, and technological contexts is underscored by contemporary technology. ZrO₂′s unique combination of properties renders it indispensable for a broad spectrum of applications, suggesting its enduring importance. This study presents the very first investigation into the physical properties, structural stability, and ground-state characteristics of sixteen distinct ZrO₂ polymorphs through the application of density functional theory (DFT). Motivated by the potential of ZrO₂ polymorphs to substitute for SiO₂, we conducted calculations to ascertain their dielectric properties. A comprehensive analysis was conducted on all structural features, and their stability was assessed. ZrO₂ polymorphs exhibit a wide bandgap with the type of bandgap also examined. Calculated zone-center phonon frequencies demonstrate the dynamical stability of ZrO₂, with existing polymorphs showing strong agreement with experimental frequencies, particularly within the monoclinic polymorph. Raman and infrared (IR) spectra of ZrO₂ polymorphs were simulated using density functional perturbation theory. ZrO₂ demonstrates notable mechanical stability, as evidenced by calculated hardness (moduli), ductility, improved ductility, and higher elasticity. Calculated optical properties, including the dielectric constant and refractive index of ZrO₂ polymorphs, play a pivotal role in optimizing their performance in various applications such as optoelectronic devices and antireflective materials.