Influence of processing parameters on the electrical response of screen printed SrFe0.6Ti0.4O3−δ thick films

A screen printing ink of SrFe0.6Ti0.4O3−δ (STFO60) nanopowders produced by Self-propagating High-temperature Synthesis (SHS) was used to produce gas sensors with high level of reproducibility at low cost. The stability and rheology of the produced ink were studied in order to obtain high quality, highly reliable films. The electrical characteristics of the sensors as a function of the firing temperature and thickness of the sensing layer were investigated. The best results were obtained stabilizing the powder with lauric acid. Laboratory bench and on-road oxygen tests demonstrated that the response of 30 μm STFO60-based resistive sensors is comparable with the one of a commercial oxygen probe.