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Phase Stability and Electrical Conductivity in Gd 2 Ti 2 O 7 ‐Gd 2 Mo 2 O 7 Solid Solutions
Author(s) -
Porat Ofer,
Heremans Catherine,
Tuller Harry L.
Publication year - 1997
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1997.tb03118.x
Subject(s) - pyrochlore , electrical resistivity and conductivity , oxidizing agent , conductivity , materials science , analytical chemistry (journal) , partial pressure , solid solution , phase (matter) , decomposition , anode , atmospheric temperature range , oxide , molybdenum , oxygen , mineralogy , chemistry , thermodynamics , metallurgy , electrode , electrical engineering , physics , organic chemistry , chromatography , engineering
Solid solutions in the Gd 2 (Ti1‐yMoy)2O7 pyrochlore system, with y = 0.1, 0.3, 0.5, and 0.7, have been investigated as potential candidates for the anode material of solid‐oxide fuel cells. The electrical conductivity, stability range, and optimal synthesis conditions of the pyrochlore phase have been explored by electrical, coulometric titration, and X‐ray diffractometry techniques. As the molybdenum content increases, the maximum conductivity increases to a value of 70 S/cm for y = 0.7 at 1000°C, whereas the stability range in the oxygen partial pressure (pO2) decreases to just over two orders of magnitude in pO2 in the temperature range of 600°‐1000°C. A decomposition reaction that leads to decreased conductivity in oxidizing atmospheres is proposed.