Customizing the elastic, thermodynamic and optical properties of Cu, Zn and Mn transition metal doped Zr2B4 ceramics: A first-principles perspective

Abstract

This study presents a first-principles-based analysis using density functional theory (DFT) to realize the impact of doping Cu, Zn and Mn transition metals on the structural, elastic, thermodynamic, and optical properties of Zr₂B₄ ceramics. The lattice parameters of Zr₂B₄ ceramics were altered due to the metal doping. Mulliken charge, Hirshfeld charge and bond lengths of all the ceramic structures were also significantly modified due to the dopants. The doping elements strongly influenced the bulk and shear modulus of Zr₂B₄ ceramics. We found that Zr₂B₄, ZrZnB₄, and ZrMnB4 are brittle, while ZrCuB₄ ceramic was ductile. Band gap is absent in the Fermi energy level of the parent and doped ceramics, resulting in metallic characteristics. The PDOS analysis showed that Mn-doped Zr₂B₄ ceramics contribute most at the Fermi level of ZrMnB₄, and B contributes the most to the ZrCuB₄ and ZrZnB₄ ceramics. The Debye temperature follows an ascending order of the form ZrCuB₄ <ZrMnB₄ <Zr₂B₄ <ZrZnB₄. A maximum Debye temperature of 1244 K was observed for ZrZnB₄ ceramics. This makes it suitable for high-temperature applications, such as thermal protection systems, hot gas valve parts, and aero-engine components. The pristine and doped Zr₂B₄ ceramics exhibited high optical conductivity in the lowest energy range. The highest static refractive index n(0) = 9.06 was recorded for ZrMnB₄ ceramics. The metallic elements Cu, Mn, and Zn are believed to be beneficial in improving the mechanical and thermodynamic properties of Zr₂B₄ ceramics. Doping with Mn improves the ductile characteristic more than doping with Zn. Thus, Mn-doped Zr₂B₄ can be used in the construction, automotive, aerospace, and manufacturing industries.