Thermodynamics and a definite large half-metallic spin gap along with a magnetic anisotropy in La-doped Ba[formula omitted]NiIrO[formula omitted

Abstract

Electron doping (i. e., by replacing Ba+2 with La+3) impact on the electronic and magnetic properties of Ba2NiIrO6 system is investigated using ab-initio calculations with the inclusion of Hubbard parameter U along with spin–orbit coupling effects. The calculated formation energies affirm the experimental realization of all motifs at ambient conditions. Whereas, the elastic properties confirm the mechanical stability, ductility, and thermal conductivity of all the structures. It is revealed that anti-ferromagnetic/ferromagnetic (FM) interaction between Ni and Ir ions are energetically stable in pristine motif having an energy band gap (Eg) of 0.70/0.35 eV using the GGA+U method without/with the inclusion of SOC effects, which is in good agreement with the recent experimental results (Feng et al., 2021). Interestingly, La-doped structures depict the half-metallic FM behavior except for 50% concentration, which results in conductivity of the spin-minority channel owing to the admixture of Ir 5d states. On the other hand, the spin-majority channels exhibit an insulating nature having a large Eg of 2.53/2.63/2.49 eV for 12.5%/25%/37.5%, which looks sufficient to restrict the spin reversal and assure high spin filtering efficiency. Moreover, La-doping leads to the existence of mixed-valence state of ＋6/＋5 having a configuration 5d3 (t2g3↑t2g0↓eg0↑eg0↓)/5d4 (t2g3↑t2g1↓eg0↑eg0↓) for Ir ion. Finally, a reasonable magneto-crystalline anisotropic constant of ∼×106 erg/cm3 in all La-doped Ba2NiIrO6 systems is predicted, which is a good signal for their potential utilization in data storage devices.