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Author Banerjee, Koyel ♦ Mukhopadhyay, Jayanta ♦ Barman, Madhurima ♦ Basu, Rajendra N.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword MATERIALS SCIENCE ♦ CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY ♦ CATHODES ♦ COBALT COMPOUNDS ♦ COMBUSTION ♦ CONCENTRATION RATIO ♦ CURRENT DENSITY ♦ DOPED MATERIALS ♦ ELECTRIC CONDUCTIVITY ♦ ELECTROCHEMISTRY ♦ FERRATES ♦ IMPEDANCE ♦ LANTHANUM COMPOUNDS ♦ POWDERS ♦ SINTERING ♦ SOLID OXIDE FUEL CELLS ♦ SPECTROSCOPY ♦ STRONTIUM COMPOUNDS ♦ SYNTHESIS ♦ TEMPERATURE DEPENDENCE ♦ THERMAL EXPANSION ♦ TRIGONAL LATTICES
Abstract Highlights: • La{sub 1−x}Sr{sub x}Co{sub y}Fe{sub 1−y}O{sub 3−δ}, x = 0.4; y = 0.2 system varying La-site (0.6–0.54) are studied. • Combustion synthesis technique is used to prepare the powder samples. • Highest electrical conductivity observed with largest A-site deficit composition. • Lowest cathode polarization is found with the same composition (0.02 Ω cm{sup 2}). • Composition with largest A-site deficiency exhibits best performance (2.84 A cm{sup −2}). - Abstract: Effect of A-site non-stoichiometry in strontium doped lanthanum cobalt ferrite (La{sub 1−x}Sr{sub x}Co{sub y}Fe{sub 1−y}O{sub 3−δ}, x = 0.4; y = 0.2) is studied in a systematic manner with variation of ‘A’ site stoichiometry from 1 to 0.94. The perovskite based cathode compositions are synthesized by combustion synthesis. Powder characterizations reveal rhombohedral crystal structure with crystallite size ranging from 29 to 34 nm with minimum lattice spacing of 0.271 nm. Detailed sintering studies along with total DC electrical conductivities are evaluated in the bulk form with variation of sintering temperatures. The electrode polarizations are measured in the symmetric cell configuration by impedance spectroscopy which is found to be the lowest (0.02 Ω cm{sup 2} at 800 °C) for cathode having highest degree of ‘A’-site deficiency. The same cathode composition exhibits a current density of 2.84 A cm{sup −2} (at 0.7 V, 800 °C) in anode-supported single cell. An attempt has been made to correlate the trend of electrical behaviour with increasing ‘A’-site deficiency for such cathode compositions.
ISSN 00255408
Educational Use Research
Learning Resource Type Article
Publisher Date 2015-12-15
Publisher Place United States
Journal Materials Research Bulletin
Volume Number 72


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