P1GS.12 - Crystal Structure and CO2 Sensing Properties of Rare-earth oxycarbonates
- 17th International Meeting on Chemical Sensors - IMCS 2018
2018-07-15 - 2018-07-19
- P-1 - Gas Sensors
- T. Suzuki, A. Sackmann, A. Staerz, U. Weimar, N. Barsan - Institute of Physical Chemistry, University of Tübingen, Tübingen (Germany), F. Lauxmann, C. Berthold - Applied Mineralogy, University of Tübingen, Tübingen (Germany)
- 541 - 542
Rare-earth oxycarbonates Ln2O2CO3 (Ln = rare-earth element) are promising materials for chemoresistive CO2 gas sensors. The previous works singled out monoclinic La2O2CO3 as the best performing member of this family of materials. However, the monoclinic structure is metastable and could be transformed into the hexagonal phase. To date there is no clear evidence about the sensing properties of hexagonal structure. In this work we are attempting to study the issues of thermal stability and CO2 sensing performance for both structure. To do so, we synthesized monoclinic and hexagonal La2O2CO3 by using two different preparation routes. Our investigations are indicating that both structures are sensitive to CO2 gas to the same degree, but the resistivity of the hexagonal La2O2CO3 is higher and the monoclinic structure may transform also under typical measurement conditions at least partially into the hexagonal structure which significantly influences the electrical properties and thereby the characteristics of the sensor.