Synthesis, crystal structure and properties of SmBaCo{sub 2−x}Fe{sub x}O{sub 5+δ}

Journal Article · Thu Aug 15 00:00:00 EDT 2013 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2013.06.001· OSTI ID:22274042

Volkova, N. E.; Gavrilova, L. Ya. ^[1]; Aksenova, T. V. ^[1]; Kolotygin, V. A.; Kharton, V. V. ^[2]

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1. Department of Chemistry, Ural Federal University, Yekaterinburg (Russian Federation)
2. Department of Materials and Ceramic Engineering, CICECO, University of Aveiro (Portugal)

The solid solution formation range in the SmBaCo{sub 2−x}Fe{sub x}O{sub 5+δ} (0≤x≤2) system examined at 1100 °C in air corresponds to 0≤x≤1.1. The crystal structure of SmBaCo{sub 2−x}Fe{sub x}O{sub 5+δ} with x≤0.5 was described as orthorhombic (space group Pmmm), and with 0.6≤x≤1.1—as tetragonal (P4/mmm). The introduction of iron into the cobalt sublattice leads to a gradual increase of the unit cell parameters and volume, accompanied with increasing oxygen content determined by thermogravimetry. The dilatometric curves collected at 25–1100 °C in air exhibit moderate nonlinearities associated with the orthorhombic→tetragonal phase transition, as confirmed by the high-temperature X-ray diffraction analysis. Temperature dependencies of the electrical conductivity measured by 4-probe dc method in the temperature range 25–1000 °C in air display maxima at 300–350 °C, whilst the conductivity decreases with iron additions. These trends were discussed in terms of the defect structure and nature of the main charge carriers in SmBaCo{sub 2−x}Fe{sub x}O{sub 5+δ}. It was also shown that SmBaCo{sub 2−x}Fe{sub x}O{sub 5+δ} is chemically stable with respect to the Ce{sub 0.8}Sm{sub 0.2}O{sub 1.9} solid electrolyte up to 1100 °S, but reacts with Zr{sub 0.85}Y{sub 0.15}O{sub 1.93} even at 900 °S. Highlights: • The solid solution formation range in the SmBaCo{sub 2−x}Fe{sub x}O{sub 5+δ} system at 1100 °C in air corresponds to 0≤x≤1.1. • The unit cell volume and oxygen content in the solid solutions increase with x. • Oxygen nonstoichiometry of SmBaCo{sub 2−x}Fe{sub x}O{sub 5+δ} solid solutions. • Temperature dependencies of the electrical conductivity exhibit maxima at the temperatures when oxygen exchange with the gaseous phase becomes significant.

• OSTI ID: 22274042
• Journal Information: Journal of Solid State Chemistry, Vol. 204; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
BARIUM
CHARGE CARRIERS
COBALT
ELECTRIC CONDUCTIVITY
IRON
IRON ADDITIONS
ORTHORHOMBIC LATTICES
PEROVSKITE
PHASE TRANSFORMATIONS
SAMARIUM
SOLID ELECTROLYTES
SOLID SOLUTIONS
SPACE GROUPS
SYNTHESIS
TETRAGONAL LATTICES
THERMAL GRAVIMETRIC ANALYSIS
X-RAY DIFFRACTION