Insight into structural, electronic, optoelectronic, dynamic, elastic, thermal and magnetic properties of pure and doped LiMgSb by nitrogen: Ab-initio calculations

In this work, ab-initio simulation has been conducted to explore and compare various properties, structural, electronic, optoelectronic, dynamic, elastic and magnetic of the pure bulk unit cell of LiMgSb and substituted by nitrogen (N). Herein, we have optimized the lattice parameter of the structure using the both approximations, generalized gradient approximation (GGA) and self-interaction correction (SIC), finding values of 6.9 and 6.7 Å, respectively. Additionally, the undoped system exhibits characteristics of a non-magnetic P-type semiconductor. The forbidden band of the compound is an indirect one at Γ-X points, aligning with existing literature, and measuring 0.742 eV and 0.95 eV under the GGA and SIC approximations, respectively. We have also investigated how the bandgap varies with the lattice parameter to analyze the influence of atomic interactions on the electronic band structure. Further analyses include the calculation of the energy photon wavelength and refractive index corresponding to the pure LiMgSb band gap. The electronic and dynamic stabilities of the compound have been confirmed through calculations of formation energies and phonon dispersion and total density of states. The bulk modulus, elastic constants, Debye temperature and melting temperature have been determined, indicating elastic stability of the system. Moreover, substitution doping the compound with N in different antisites positions with various concentrations has revealed ferromagnetic stability in Li1-xNxMgSb and LiMg1-xNxSb. Emphasis has been placed on the half-metallic behavior of the doped alloys, with an estimation of the Curie temperature utilizing mean field theory. Hence, the predicted compounds hold potential for multifaceted applications in spintronics and optoelectronics.