Examining optical, elastic, electronic, and structural properties of NaZrX3 (X = Cl and F) perovskite compounds: DFT study

Abstract

This study explores the structural, elastic, electronic, and optical properties of NaZrX₃ (X = Cl and F) perovskite compounds using density functional theory (DFT) with the TB-mBJ approximation. Both compounds crystallize in a cubic lattice (space group Pm3̅m) and fulfill the Born stability criteria, with elastic constants confirming their ductile nature (B/G > 1.75) and anisotropic elastic response (A ≠ 1). The absence of imaginary frequencies in the phonon dispersion curves confirms the thermodynamic stability of both materials. Electronic structure analysis reveals metallic behavior arising from the overlap of valence and conduction bands. In both NaZrF₃ and NaZrCl₃, the metallic character is dominated by Zr d-orbitals, while spin–orbit coupling slightly modifies the band dispersion without opening a bandgap. Optical properties, evaluated over 1–10 eV, show high conductivity, significant absorption, and strong reflectivity in the low-energy range, indicating potential for ultraviolet and optoelectronic applications. The substitution of Cl with F enhances the bulk modulus, increases the pressure derivative, reduces the lattice constant, and lowers the ground-state energy. These findings establish NaZrX₃ as promising materials for next-generation electronic and optical devices.