First-principles Study on Structural and Electronic Properties: The Li Based of Full-Hesulter Alloys LiGa2Ir

Abstract

Abstract: Due to their excellent electronic properties, full-Heusler compounds have become one of the most interesting families of alloys in superconductivity. More recently, computational methods have been actively employed to support the rapid discovery of new complete Heusler alloys by identifying stable compositions with desired properties. Therefore, we investigated the stability, structure, and electronic properties of the lithium-based Heusler compound LiGa₂Ir using first-principles calculations. We explored the effects of exchange-correlation, namely Perdew-Burke-Ernzerhof (PBE), PBE+U, and Tran-Blaha modified Becke-Johnson potentials, as well as the effect of heavy metal spin-orbit coupling on these Heusler compounds. The results show that LiGa₂Ir is energetically stable, and the obtained lattice parameter value (a = 6.0927 Å) agrees with the experimental results. LiGa₂Ir exhibits metallic behavior under all three exchange-correlation estimates. A much stronger spin-orbit coupling effect is observed for electronic states with energies below the Fermi level E_F, especially in the Tran-Blaha modified Becke-Johnson approximation. Significant spin-orbit coupling effects are evident from the total and partial density of states figures, especially in the energy range from -4.5 eV to -2 eV. The contributions from Ir-d and Ga-p orbitals are the largest, while the contribution from the Li atom is small. Our findings will benefit future theoretical and practical work on lithium-based full-Heusler alloys.