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Title: Proton conduction and chemical stability of (La{sub 0.5}Sr{sub 0.5})(Mg{sub 0.5+y}Nb{sub 0.5-y})O{sub 3-{delta}}

Journal Article · · Materials Research Bulletin
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  1. Department of Applied Chemistry, Faculty of Engineering, Kyushu University, 744 Motooka, Nishiku, Fukuoka 819-0395 (Japan)

Electrical conduction properties of complex perovskite-type oxides in the (La{sub 0.5}Sr{sub 0.5})(Mg{sub 0.5+y}Nb{sub 0.5-y})O{sub 3-{delta}} (y = 0.02-0.06) series at intermediate-high temperatures were investigated; introduction of protons by hydration of oxide-ion vacancies was expected by increasing the Mg/Nb ratio from unity. The conductivity depended on y and a maximum conductivity was obtained at y = 0.04: {sigma} = 4.9 x 10{sup -6} S cm{sup -1} at 400 deg. C in wet H{sub 2} atmospheres. From electromotive force measurements of hydrogen and water vapor concentration cells, electrical conduction in wet H{sub 2} atmospheres can be attributed to ionic conduction, and proton conduction is dominant below 700 deg. C. Unlike other perovskite-type proton conductors, (La{sub 0.5}Sr{sub 0.5})(Mg{sub 0.54}Nb{sub 0.46})O{sub 3-{delta}} was stable in CO{sub 2} atmospheres even in the low-intermediate temperature region due to dilution of reactive strontium by lanthanum.

OSTI ID:
21199690
Journal Information:
Materials Research Bulletin, Vol. 44, Issue 2; Other Information: DOI: 10.1016/j.materresbull.2008.04.018; PII: S0025-5408(08)00152-9; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
Country of Publication:
United States
Language:
English