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SOLID STATE IONICS OF OXIDES
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| Susan Wang | Wenquan Gong | Manoj Yadav |
| We investigate complex oxide materials
that have applications in high temperature ionic devices, such as fuel
cells, oxygen transport membranes and sensors. The major part of our work
centers on mixed metal oxides with the ABO3 perovskite structure. At present
the database of perovskite oxide ionic properties is limited and we
investigate new compositions to establish structure-property relationships.
We also investigate the synthesis of new oxide structure types. The
discovery of a new class of (Ba,Sr)-Co-O oxides is one recent example.
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We use a variety of techniques to
characterize the surface reactivity and bulk transport properties of
materials, which together determine device performance. We use oxygen
permeation through membranes, electrical conductivity relaxation, dc
conductivity, ac impedance spectroscopy and other techniques to establish
transport properties at high temperature in a variety of atmospheres. We
also determine compound stoichiometry using thermogravimetric analysis and
coulometric titration techniques. Isotope exchange experiments also give
important and complementary information about ionic transport. We
collaborate with C. A. Mims and P. van der Heide to investigate transport
across interfaces using secondary ion mass spectroscopy (SIMS). Experimental
measurements are combined with modeling studies to interpret the transport
behavior.
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| Research Supported by: National Science Foundation, Department of Energy, |
| Robert A. Welch Foundation, Texas Center for Superconductivity. |