Electrical properties of lanthanum chromite based ceramics in hydrogen and oxidizing atmospheres at high temperatures. Final report
Several results regarding the effect of hydrogen on lanthanum chromite were determined. Thermally-activated diffusion of hydrogen through La(Mg)CrO/sub 3/ was found with a high activation energy. It was found that its electrical conductivity drops drastically, especially at low temperature, after exposure to hydrogen at high temperature. Also, the curvature of most of the conductivity plots, as well as the inability to observe the Hall effect, lends support to the proposal by Karim and Aldred that the small-polaron model which predicts thermally activated mobility is applicable to doped lanthanum chromite. From differential thermal analysis an apparent absorption of hydrogen near 300/sup 0/C was noticed. Upon cooling the lanthanum chromite in hydrogen and subsequently reheating it in air, desorption occurred near 170/sup 0/C. The immediate purpose of this study was to determine whether hydrogen has a deleterious effect on lanthanum chromite in solid oxide fuel cells.
- Research Organization:
- Montana State Univ., Bozeman (USA). Dept. of Physics
- DOE Contract Number:
- AS05-79ET15415
- OSTI ID:
- 6305381
- Report Number(s):
- DOE/ET/15415-1; ON: DE81028306
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
36 MATERIALS SCIENCE
CHROMIUM OXIDES
ELECTRICAL PROPERTIES
HIGH-TEMPERATURE FUEL CELLS
CONNECTORS
HYDROGEN
THERMAL DIFFUSION
LANTHANUM OXIDES
CERAMICS
DESORPTION
DIFFERENTIAL THERMAL ANALYSIS
ELECTRIC CONDUCTIVITY
HALL EFFECT
HIGH TEMPERATURE
MATERIALS TESTING
SOLID ELECTROLYTES
TEMPERATURE DEPENDENCE
CHALCOGENIDES
CHROMIUM COMPOUNDS
CONDUCTOR DEVICES
DIFFUSION
DIRECT ENERGY CONVERTERS
ELECTRICAL EQUIPMENT
ELECTROCHEMICAL CELLS
ELECTROLYTES
ELEMENTS
EQUIPMENT
FUEL CELLS
LANTHANUM COMPOUNDS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
TESTING
THERMAL ANALYSIS
TRANSITION ELEMENT COMPOUNDS
300503* - Fuel Cells- Materials
Components
& Auxiliaries
360204 - Ceramics
Cermets
& Refractories- Physical Properties