Aerosol Co-deposition of Ceramics: Composites of SrTi0.65Fe0.35O3-δ and Al2O3

Titelangaben

Exner, Jörg ; Fuierer, Paul ; Moos, Ralf:
Aerosol Co-deposition of Ceramics: Composites of SrTi0.65Fe0.35O3-δ and Al2O3.
2015
Veranstaltung: 7th International Conference on Electroceramics (ICE2015), State College , 13.-16.05.2015 , State College, Pennsylvania, USA.
(Veranstaltungsbeitrag: Kongress/Konferenz/Symposium/Tagung , Poster )

Angaben zu Projekten

Abstract

A perovskite solid solution of strontium titanate and strontium ferrate, specifically SrTi0.65Fe0.35O3-δ (STF), is a ceramic that has received much attention for resistive oxygen sensing due to its temperature-independent characteristics. The object of this study is to deposit well-defined mixtures of STF and Al2O3 by Aerosol Co-deposition (AcDc). Of interest is whether electrical properties can be fine-tuned by different amounts of Al2O3 (which serves as a passive filler and electrically insulating component).

Four mixtures of STF35 with 20 to 80 vol.-% Al2O3 were prepared. The AcDc process was performed using a custom-made aerosol deposition apparatus. Films were sprayed on alumina for SEM/EDS and XRD analysis and on screen printed electrodes to study the temperature and oxygen partial pressure (pO2) characteristics of the conductivity.

Films of the STF/Al2O3-mixtures with thicknesses between 10 and 20 μm were successfully deposited. The mixing ratio within the films showed a slight change in the composition compared to the sprayed powder. Except for the film with 80 vol.-% Al2O3, all films exhibit a similar electrical behavior. As intended, higher amounts of Al2O3 resulted in a decreased overall conductivity. Due to thermal annealing during initial heating up to 800 °C, the conductivity increased by 2 orders of magnitude and remained constant afterward. Between 700 and 800 °C, films retain their temperature independent conductivity as well as their typical pO2-dependeny, with a slope of m = 0.2 per decade of oxygen partial pressure change.