Structural phase transitions at high-temperature in double perovskite Sr2GdRuO6

• Published in: Physica. B, Condensed matter Vol. 407; no. 16; pp. 3150 - 3154
• Main Authors: Triana, C.A., Corredor, L.T., Landínez Téllez, D.A., Roa-Rojas, J.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.08.2012; Elsevier
• Subjects: Complex perovskite; Condensed matter; Condensed matter: structure, mechanical and thermal properties; Crystal structure; Diffraction; Displacements (lattice); Equations of state, phase equilibria, and phase transitions; Evolution; Exact sciences and technology; Inorganic compounds; Lattice parameters; Perovskites; Phase transformations; Phase transitions; Physics; Solid-solid transitions; Specific phase transitions; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; X-ray powder diffraction; Complex perovskite; Phase transitions; X-ray powder diffraction; Crystal structure; Rietveld method; Space groups; Phase transformations; Ruthenium oxides; Perovskites; Ceramics; XRD; High temperature; Lattice parameters; Monoclinic lattices; Gadolinium oxides; Anisotropy; Quaternary compounds; Strontium oxide
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2011.12.050

The crystal structure evolution of the Sr2GdRuO6 complex perovskite at high-temperature has been investigated over a wide temperature range between 298K≤T≤1273K. Powder X-ray diffraction measurements at room temperature and Rietveld analysis show that this compounds crystallizes in a monoclinic perovskite-type structure with P21/n (#14) space group and the 1:1 ordered arrangement of Ru5+ and Gd3+ cations over the six-coordinate M sites, with lattice parameters a=5.81032(8)Å, b=5.82341(4)Å, c=8.21939(7)Å, V=278.11(6)Å3 and angle β=90.311(2)o. The high-temperature analysis shows that this material suffers two-phase transitions. At 373K it adopts a monoclinic perovskite structure with I2/m space group, and lattice parameters a=5.81383(2)Å, b=5.82526(4)Å, c=8.22486(1)Å, V=278.56(2)Å3 and angle β=90.28(2)o. Above of 773K, it suffers a phase transition from monoclinic I2/m to tetragonal I4/m, with lattice parameters a=5.84779(1)Å, c=8.27261(1)Å, V=282.89(5)Å3 and angle β=90.02(9)o. The high-temperature phase transition from monoclinic I2/m to tetragonal I4/m is characterized by strongly anisotropic displacements of the anions.