| Autor: |
Glot, A. B., Sandoval-Garcia, A. P., Gaponov, A. V., Bulpett, R., Benjamin Jones, Jimenez-Santana, G. |
| Jazyk: |
angličtina |
| Rok vydání: |
2009 |
| Předmět: |
|
| Zdroj: |
Abertay University |
| ISSN: |
1833-122X |
| Popis: |
Tin dioxide based varistor ceramics SnO2-Co3O4-Nb2O5-Cr2O3-xCuO (x=0; 0.05; 0.1 and 0.5) were made and their electrical properties were studied. The highest nonlinearity coefficient and electric field (at current density 10-3 A cm-2) were obtained for 0.1 mol.% CuO addition. It was observed that low-field electrical conductivity is increased with relative humidity, therefore, materials obtained exhibit double function of varistor and humidity sensor. The highest humidity sensitivity coefficient is found for SnO2-Co3O4-Nb2O5-Cr2O3 ceramics (without CuO). Observed varistor and humidity-sensitive properties are explained in the frames of grain-boundary double Schottky barrier concept as a decrease of the barrier height with electric field or relative humidity. Using suggested simple theory and data obtained on isothermal capacitance relaxation, the energy of the grain-boundary monoenergetic trapping states were estimated. These values are less than found for activation energy of electrical conduction (as a measure of the barrier height). These observations confirm the barrier concept. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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