Investigation of the Ag2SO4 — BaSO4 binary system from an SOx sensor point of view
| Autor: | Kamal Singh, R. V. Joat, S. S. Bhoga |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Materials science
General Chemical Engineering General Engineering Analytical chemistry General Physics and Astronomy Electrolyte Conductivity Crystallography Electrical resistivity and conductivity General Materials Science Binary system Thermal analysis Powder diffraction Phase diagram Eutectic system |
| Zdroj: | Ionics. 8:470-478 |
| ISSN: | 1862-0760 0947-7047 |
| DOI: | 10.1007/bf02376063 |
| Popis: | The binary phase diagram of Ag2SO4 — BaSO4 system is proposed using X-ray powder diffraction, thermal analysis (DTA/DSC), scanning electron microscopy, and electrical conductivity results. About 5 mol-% BaSO4 is soluble in β-Ag2SO4. The two-phase (Ag2SO4+BaSO4) mixture exists for 10–90 mol-% of BaSO4 between room temperature and 578 °C. An eutectic of 578 °C exists of the composition 70Ag2SO4+30BaSO4 The conductivity maximum within the solid solubility limits is due to the generation of extrinsic vacancies and lattice expansion as a result of partial substitution of the bigger aliovalent Ba2+ for the Ag+-ions. The eutectic composition shows the maximum conductivity in the entire binary system due to the minimum in grain size, thereby providing a maximum surface ion conducting path. About 1 min response time of the sensor based on using the eutectic composition, as solid electrolyte, is much shorter than that of the sensor with pure Ag2SO4. |
| Databáze: | OpenAIRE |
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