DFT Study of the Antiferromagnetic Barium Ruthenate Triple Perovskites Ba₃MRu₂O₉ (M = Fe, Co, and Ni) for Spintronic Applications

Density-functional theory (DFT) is utilized to study the crystal structure, geometry, and magnetic and electronic properties of the triple perovskites Ba₃MRu₂O₉ (M = Fe, Co, and Ni) in hexagonal phase with space group P6₃/mmc. Generalized gradient approximation plus Hubbard potential is found to be an effective potential for the treatment of these perovskites. Spin-orbit coupling with Hubbard U (GGA+SOC+U) is also applied to analyze its effect on the understudy compounds. The optimized crystal structures and geometries are consistent with the experimental reported results. The stability of these perovskites is described by cohesive and formation energies. The antiferromagnetic (AFM) nature of all these perovskites is confirmed by stable magnetic phase energies and magnetic susceptibility. The electronic band profiles in the AFM phase and electrical resistivities confirm that these perovskites are metallic in nature. Metallicity as well as magnetism in these compounds is due to d-state electrons of the M and Ru atoms. The metallic AFM nature reveals that these compounds are promising materials for magnetic cloaking, high-speed switching devices, and spintronic applications.