First Principle Study of Structural, Electronic, Elastic, and Magnetic Properties of Half-Heusler Compounds ScTiX (X = Si, Ge, Pb, In, Sb, and Tl)

Abstract

Herein, we report the study of half-Heusler ScTiX (X = Si, Ge, Pb, In, As, and Tl) compounds for the first time employing the scheme of density functional theory (DFT). The influence of on-site Coulomb interactions is taken into account, and simulations are conducted in generalized gradient approximation with the added Hubbard U term (GGA + U). All the compounds were observed to have a narrow band gap on the spin-down configuration. Though spinning the majority channel (spin-up), it is found to be metallic. Consequently, all compounds are semi-metallic or half-metallic and 100% of spin polarized at the Fermi level. Various features, comprising structural, magnetic, elastic, and electronic properties, are calculated through full-potential linearized augmented plane wave (FP-LAPW) method, since they are incorporated in the computer simulation package of WIEN2k. Equilibrium lattice constants are observed for all the compounds which exist within the domain of 6.4–6.8 A°. The IRelast package is already integrated in WIEN2K that has been used for the elastic properties. Elastic features reflect the brittle character of all the material. The total magnetic moments for all such materials are greater than 3 μB, i.e., 3 μB of MTot. Therefore, the compounds show a strong ferromagnetic behavior. These are therefore expected to be used as shape base for thin layers within metastable situations for spintronic applications. The resulted elastic properties show that ScTiSi is ductile, while all other five compounds represent brittle nature. Above findings delight the prospect of ScTiX (X = Si, Ge, Pb, In, As and Ti) compounds in developing half-metallic HH compounds for spintronics and memory storage appliances.