Structural, electronic and magnetic properties of a symmetrical FeReO terminated (001)-oriented slab of double perovskite Sr2FeReO6

Abstract

The structural, electronic and magnetic properties of a 9-layer symmetrical FeReO terminated (001)-oriented slab of the double perovskite Sr2FeReO6 have been studied by using the first-principles projector augmented wave (PAW) potential within the generalized gradient approximation (GGA) taking into account the on-site Coulomb repulsive U (U = 2.0 eV for Fe and 1.0 eV for Re). An outwards relaxation is observed for each layer of the first four layers and the accompanying layer's rumpling decreases successively for layer 1, layer 3 and layer 5 as well as for layer 2 and layer 4. Along the Fe–O–Re–O–Fe or Re–O–Fe–O–Re chain, the oxygen atom is closer to the adjacent Re atom than to the adjacent Fe atom. The half-metallic nature with a complete (100%) spin polarization at the Fermi level ensures that the symmetrical FeReO terminated (001)-oriented slab of the double perovskite Sr2FeReO6 has the potential for application in spintronics devices. The Jahn–Teller structural distortions and the outward relaxations lead to the differences between pz state and similar px and py states, between dxy state and similar dxz and dyz states as well as between dz2 and dx2−y2. The connecting charge distributions along each Fe–O–Re–O–Fe or Re–O–Fe–O–Re chain show that the hybridizations between Fe 3d and 4s, O 2s and 2p, as well as Re 5d and 6s orbitals are fairly significant.