A.4.4 - Langasite-based Microbalance for Determination of the Non-stoichiometry in Praseodymium-Cerium Oxide Thin Films at Elevated Temperatures
- AMA Conferences 2017
2017-05-30 - 2017-06-01
- Proceedings Sensor 2017
- A4 - Gas Sensors I
- S. Schröder, H. Fritze - Clausthal University of Technology, Goslar (Germany)
- 98 - 103
The oxygen partial pressure dependent non-stoichiometry of praseodymium-cerium oxide thin films (Pr0.1Ce0.9O2-δ, PCO) is investigated at temperatures between 700 and 900 °C. The non-stoichiometry of PCO is determined gravimetrically using a high-temperature microbalance consisting of piezoelec-tric langasite (La3Ga5SiO14) resonators. Shifts of the resonance frequency are correlated with mass changes caused by oxygen incorporation/release using the Sauerbrey equation and converted into the oxygen non-stoichiometry of PCO.
Chemical and mechanical properties of the PCO films might influence the resonance frequency. Sin-gle-side deposition of PCO onto the resonators results in calculated non-stoichiometry values which exceed literature data for bulk PCO. A potential explanation is mechanical bending of the resonators due to thermo-chemical expansion. Resonators coated on both sides with PCO show smaller frequen-cy shifts corresponding to a non-stoichiometry of up to δ = 0.07, which are close to literature data.