Temperature-independent resistive oxygen exhaust gas sensor for lean-burn engines in thick-film technology

Title data

Moos, Ralf ; Rettig, Frank ; Hürland, Armin ; Plog, Carsten:
Temperature-independent resistive oxygen exhaust gas sensor for lean-burn engines in thick-film technology.
In: Sensors and Actuators B: Chemical. Vol. 93 (2003) Issue 1-3 . - pp. 43-50.
ISSN 0925-4005
DOI: https://doi.org/10.1016/S0925-4005(03)00333-2

Official URL:

Abstract in another language

Strontium titanate based materials (SrTi0.65Fe0.35O3−δ; STF or La0.05Sr0.95Ti0.65Fe0.35O3−δ; LSTF) are suggested in the literature as resistive oxygen gas sensors due to their temperature-independent but oxygen concentration-dependent resistance characteristic.

This contribution reports on the difficulties that had to be overcome by trying to transfer the properties of the pure material to a real exhaust gas compatible thick-film sensor device. Two main problems are discussed: the transfer to thick-film technique and the sensor behavior in real exhaust gas. In order to maintain the properties of the pure material, an additional diffusion barrier layer between substrate and sensor film turned out to be essential. A thick-film spinel layer (SrAl2O4) was shown to give the best performance. By using this additional layer, all the properties of the pure material were successfully transferred to a thick-film gas sensor device.

During the real exhaust gas experiments a strong deterioration of the sensor characteristic due to sulfur dioxide in the exhaust gas was observed. The poor stability against sulfur compounds in the exhaust seems to be a problem of the earth alkaline constituent of the titanate sensor material and cannot be improved easily. However, by applying an additional newly developed porous sulfur adsorber film made from earth alkaline carbonates as sulfur adsorbing components, long-term stable exhaust gas sensors can be obtained.

Further data

Item Type:	Article in a journal
Refereed:	Yes
Institutions of the University:	Faculties > Faculty of Engineering Science Faculties > Faculty of Engineering Science > Chair Functional Materials > Chair Functional Materials - Univ.-Prof. Dr.-Ing. Ralf Moos Faculties Faculties > Faculty of Engineering Science > Chair Functional Materials Profile Fields > Advanced Fields > Advanced Materials Research Institutions > Research Centres > Bayreuth Center for Material Science and Engineering - BayMAT Profile Fields Profile Fields > Advanced Fields Research Institutions Research Institutions > Research Centres
Result of work at the UBT:	Yes
DDC Subjects:	600 Technology, medicine, applied sciences > 620 Engineering
Date Deposited:	03 Feb 2015 06:45
Last Modified:	05 Apr 2016 06:40
URI:	https://eref.uni-bayreuth.de/id/eprint/6161