The structural, electronic, and optical properties of the d0 full-Heusler alloys Li2BaZ (Z = C, Ge, Si) in the XA (Hg2CuTi-type) configuration, were investigated using first-principles calculations based on density functional theory (DFT) with the WIEN2k software package. The results revealed that all the compounds are energetically stable in the XA structure. Electronic band structure calculations, employing the modified Becke–Johnson (mBJ) potential, confirmed the semiconducting nature of these alloys, with Li2BaC exhibiting an indirect band gap of 0.539 eV, while Li2BaGe and Li2BaSi display direct band gaps of 0.571 and 0.536 eV, respectively. Optical property analysis demonstrated strong dielectric responses, high refractive indices, and significant absorption in the visible to ultraviolet ranges, with reflectivity peaks reaching 62% for Li2BaGe and Li2BaSi in the visible range. These findings suggest potential applications in optoelectronic devices, radiation shielding, and photonic coatings. The study provides comprehensive insights into the fundamental properties of these alloys, paving the way for further experimental exploration.
Amari et al. (Fri,) studied this question.