First-principles investigation of the physical properties of indium based fluoroperovskites InAF3 (A = Ca, Cd and Hg)

Abstract

The theoretical study is performed to investigate the structural, elastic, electronic and optical properties of Indium based fluoroperovskites InAF3 (A = Ca, Cd, and Hg) based on the Density Functional Theory (DFT) using the Full-Potential Linearized Augmented Plane Wave (FP-LAPW) method implemented in WIEN2K. Generalized Gradient Approximation (GGA) with Hubbard term (GGA + U) is employed for the incorporation of exchange-correlation energy. The optimized lattice constants are found in the range of 4.51 Å to 4.69 Å. The calculated values of elastic constants show that compounds satisfy the stability criteria for a cubic system. It has also been observed that all the compounds are ductile and show anisotropic behavior. Calculated bandgaps of InCaF3 and InCdF3 are 3.66 eV and 3.29 eV, respectively, exhibiting direct band nature. The InHgF3 is found to be an indirect bandgap material having the value of 1.59 eV. The significance of states contributed by each element is inferred from the total and partial density of state plots. The optical characteristics are discussed and analyzed in a broad energy range (with specific range shown 0–30 eV) using important parameters such as optical conductivity and reflectivity, refractive index, extinction coefficient, and absorption coefficient. The results are communicated for the first time for understudy Indium based compounds.