Oxygen Sensor Using Perovskite-Type Oxides
1986; American Chemical Society; Linguagem: Inglês
10.1021/bk-1986-0309.ch005
ISSN1947-5918
AutoresYasuhiro Shimizu, Yoshiki Fukuyama, Hiromichi Arai, Tetsuro Seiyama,
Tópico(s)Advanced Sensor Technologies Research
ResumoThe perovskite-type oxides (ABO3) were studied from the viewpoints of application for oxygen sensors. Among the perovskite-type oxides examined, SrTiO3 showed a high sensitivity to oxygen in the temperature range from 550 to 800 °C in the "lean-burn" region (102 Pa < PO2 102 Pa and showed a p-type semiconductive nature. As for SrSnO3, no significant changes in the conductivity were observed in the "lean-burn" region, since the change of the conduction mechanism from p-type to n-type occurred in this region. The resistivity characteristics of the specimens were also investigated in the exhaust gas of propane-oxygen combustion. SrSnO3 was promising for a combustion monitoring sensor, judging from the magnitude of the decrease in the resistivity at λ = 1 with decreasing λ and good reproducibility of resistivity characteristics (λ ; oxygen excess ratio). On the other hand, the magnitude of the decrease in the resistivity of SrTiO3 at λ = 1 was smaller than that of SrSnO3, because the conduction mechanism of SrTiO3 changed from p-type to n-type at PO2 = 10-2 Pa. The effects of B site partial substitution of SrTiO3 on the oxygen partial pressure dependence of the conductivity were also investigated.
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