Metastable In4Sn3O12 in Sensor Application
- 10. Dresdner Sensor-Symposium 2011
2011-12-05 - 2011-12-07
- Innovative Sensorlösungen II
- J. Kemmler - Tübingen, S. Pokhrel, L. Mädler - Bremen, N. Barsan, U. Weimar - Tübingen
- 241 - 244
In4Sn3O12 is considered as a high temperature phase of the binary In2O3 - SnO2 mixture. As shown by Isomäki et al, this specific phase is stable in the temperature region of about 1.600 °C to, depending on the mole fraction, 1.950 °C. Furthermore, this phase can be found throughout almost the whole range of the mole fraction (0,1-~1 SnO2). As a matter of fact, by applying Flame Spray Pyrolysis (FSP) to synthesize this ITO-like metal oxide, these temperatures are reached during combustion of the organometallic precursors. Rapid quenching of the nascent nanocrystalline particles results in the formation of a highly porous layer, solely containing particles of In4Sn3O12, when combusting a solution containing 43 wt% Sn in In2O3.
Applying this layer as a sensing layer for formaldehyde detection showed, that the reported phase is by far more stable at room temperature and operating conditions (200 - 350 °C) than expected. For the evaluation of the sensors stability, the baseline resistance as well as the evolution of the sensor signal over time is taken into account.