Theoretical investigation of Ca0.75Cd0.25X (X = S, Se), a novel ternary alloy, in light of its structural, elastic, electronic, and optical properties

Abstract

In the current work, using the full-potential linearized augmented plane wave (FP-LAPW) method implemented in the Wien2k code and framed within density functional theory (DFT), we present a theoretical analysis of the structural, elastic, electronic, and optical properties of binary compounds CaX (X = S, Se), and ternary alloys Ca0.75Cd0.25X (X = S, Se). We employ the Wu-Cohen approximation to estimate the exchange-correlation potential. This approximation enables us to accurately determine the elastic and structural properties of the studied materials. Furthermore, we enhance the accuracy of our electronic structure calculations by incorporating the modified Becke Johnson (mBJ) potential. Our calculations for the structural, elastic, electronic and optical parameters of the binary compounds are compared with previously reported studies and are found to be consistent with the available data in the literature. We observe that our materials are semiconductors characterized by an indirect band gap energy (Γ-X) for CaX and (M-Γ) for Ca0.75Cd0.25X. Furthermore, the outcomes of our computations demonstrate that our materials exhibit brittleness, as determined by evaluating the elastic constants and corresponding elastic moduli. To our knowledge, the ternary alloys are investigated for the first time and the obtained results are predictions and still need to undergo experimental validation.