Structural and electronic behavior of Sr2GdRuO6 complex perovskite

We report experimental and theoretical study of crystallographic lattice and electronic structure of Sr2GdRuO6 complex perovskite, which is used as precursor in the fabrication process of superconducting ruthenocuprate RuSr2GdCu2O8. Samples were produced by the standard solid state reaction. Rietveld refinement of experimental X-ray diffraction patterns shows that material crystallizes in a monoclinic structure, which belongs to the P2(1)/n (#14) space group, with lattice parameters a = 5.8019(6) angstrom. b = 5.8296(5) angstrom, c = 8.2223(7) angstrom, and tilt angle beta = 90.258 degrees. Calculations of electronic structure were performed by the density functional theory. The exchange and correlation potentials were included through the LDA+U approximation. Density of states (DOS) study was carried out considering the two spin polarizations. Results show Gd are majority responsible for the magnetic character in this material, but Ru contribution is also relevant because d-orbital is closer to Fermi level. Theoretical results evidence that Sr2GdRuO6 Material behaves as a magnetic semiconductor, with 20 mu(B) effective magnetic moment. (C) 2009 Elsevier B.V. All rights reserved.