biostudies-literatureUnknown10(1)Huang HLLocal density approximation plus on-site Coulomb interaction U electronic structure calculations reveal that layered perovskite oxide Sr2RuO4 exhibits the ferromagnetic (FM) half-metallic ground state, which is nearly degenerate with the antiferromagnetic (AFM) phase with a slightly higher total energy. The nearly degenerate FM/AFM total energies provide a reasonable explanation for the experimentally observed spin-fluctuation. In addition, a dumbbell-shape 4d - t2g recombined dxz?-?dyz orbital ordering on the Ru sublattice is obtained owing to the on-site Coulomb interaction U associated with the elongated RuO6 octahedron local structure. The discovered orbital ordering is robust against the spin-orbit interaction as well as the surface terminations. Our findings unravel the on-site Coulomb correlation as the driving force of the Ru-4d orbital ordering as well as the inherent magnetic degeneracy.Scientific reports7089https://www.ebi.ac.uk/biostudies/studies/S-EPMC7184627biostudies-literatureOrbital ordering and magnetism in layered Perovskite Ruthenate Sr2RuO4.PMC7184627Huang HLJeng HTfalseOrbital ordering and magnetism in layered Perovskite Ruthenate Sr2RuO4.Local density approximation plus on-site Coulomb interaction U electronic structure calculations reveal that layered perovskite oxide Sr2RuO4 exhibits the ferromagnetic (FM) half-metallic ground state, which is nearly degenerate with the antiferromagnetic (AFM) phase with a slightly higher total energy. The nearly degenerate FM/AFM total energies provide a reasonable explanation for the experimentally observed spin-fluctuation. In addition, a dumbbell-shape 4d - t2g recombined dxz?-?dyz orbital ordering on the Ru sublattice is obtained owing to the on-site Coulomb interaction U associated with the elongated RuO6 octahedron local structure. The discovered orbital ordering is robust against the spin-orbit interaction as well as the surface terminations. Our findings unravel the on-site Coulomb correlation as the driving force of the Ru-4d orbital ordering as well as the inherent magnetic degeneracy.2020-01-01T00:00:00Z2020 Apr2020-05-22T18:39:16Z2020-05-22T18:39:16ZS-EPMC71846273234144610.1038/s41598-020-63415-8