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Title: Constitution of the Sr-Ni-O system

The constitution of the Sr-Ni-O system was studied experimentally for the first time. Samples were prepared either from SrCO{sub 3} and NiO or from Sr(NO{sub 3}){sub 2} and Ni(NO{sub 3}){sub 2}.6H{sub 2}O and characterized by high-temperature X-ray powder diffraction, scanning electron microscopy, thermogravimetric and differential thermal analyses. In the SrO-NiO quasibinary system an eutectic reaction: liquid-bar SrO+NiO was found to occur at 1396+/-5{sup o}C, while the homogeneity range of terminal solid solutions is negligible. Thermodynamic calculations using the regular solution model for the liquid and rocksalt-type phases were employed to predict liquidus and solidus curves. Three ternary compounds, SrNiO{sub 2.5}, Sr{sub 5}Ni{sub 4}O{sub 11}, and Sr{sub 9}Ni{sub 7}O{sub 21} were observed in the samples prepared from nitrate solutions, but only Sr{sub 9}Ni{sub 7}O{sub 21} was proved to be thermodynamically stable in air up to 1030+/-6{sup o}C. When heating in air, SrNiO{sub 2.5} and Sr{sub 5}Ni{sub 4}O{sub 11} were found to transform irreversibly into a mixture of Sr{sub 9}Ni{sub 7}O{sub 21} and NiO. Isothermal section of the SrO-NiO-O subsystem, which represents phase equilibria at 950-1030{sup o}C as well as an isobaric section of the Sr-Ni-O system in air were constructed.
Authors:
 [1]
  1. Max-Planck-Institut fuer Metallforschung and Institut fuer Nichtmetallische Anorganische Materialien der Universitaet Stuttgart, Heisenbergstrasse 3, D-70569 Stuttgart (Germany). E-mail: zinkevich@mf.mpg.de
Publication Date:
OSTI Identifier:
20729090
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 178; Journal Issue: 9; Other Information: DOI: 10.1016/j.jssc.2005.06.035; PII: S0022-4596(05)00291-4; Copyright (c) 2005 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; DIFFERENTIAL THERMAL ANALYSIS; EUTECTICS; HEATING; NICKEL NITRATES; NICKEL OXIDES; PHASE DIAGRAMS; SCANNING ELECTRON MICROSCOPY; SOLID SOLUTIONS; STABILITY; STRONTIUM NITRATES; STRONTIUM OXIDES; THERMAL GRAVIMETRIC ANALYSIS; X-RAY DIFFRACTION