Elastic anisotropies and electronic properties of cubic spinel CuGa₂O₄: A DFT calculation

The aim of this work is to study the structural and elastic properties of the spinel CuGa2O4. The quantum DFT approximation used in this study was applied to Copper Gallium Oxide with a space group Fd3̅m (227) and crystallized in a cubic structure, with unit-cell parameters: a = 8.4996, c = 5.8172 Å. Structural characteristics of a material can be investigated without making physical measurements by optimizing the first-principles computation. This is achieved by utilizing the CASTEP code based on the pseudo-potential plane-wave within the Material Studio software. Known as Copper Gallium Oxide, this compound falls under the category of spinel oxides. It is a type of mixed metal oxide where copper (Cu2+) and gallium (Ga3+) ions are combined with oxygen (O2-) ions.

Spinel-structured CuGa2O4 mixed oxide, with a narrow band-gap of 1.5 eV, exhibits intriguing properties. These characteristics have motivated investigations into its potential applications, notably its magnetic, dielectric, and optical traits, as well as its promise in the field of photocatalytic pollutant degradation. In this study, CuGa2O4’s geometrical optimization was performed using a semi-local generalized gradient approximation (GGA) with the Perdew-Burke-Ernzerhof (PBE) for exchange-correlation functional. After optimization, records of bandgap and DOS were analyzed to understand its electronic properties. The electronic properties of CuGa2O4 were determined by examining the electronic band structure and density of states, which are indicative of CuGa2O4 being a narrow-gap semiconductor with a direct band gap. Additionally, we determined the elastic constants, bulk, shear, and Young’s moduli, Pugh ratio, Poisson’s ratio, and universal anisotropy. All studied compositions of this compound show structural stability