A new solid-electrolyte impedance-metric NOx sensor device composed of a lithium ionic
solid electrolyte: Li1.5Al0.5Ti1.5(PO4)3 (LATP) as a transducer and ceramic oxides (perovskite-type
oxides, TiO2, SnO2, etc) as a receptor, respectively, have been systematically investigated for the
detection of NOx (NO and NO2 ) in the range 10 – 200 ppm at 400 - 500°C. Responses of the sensors
were able to divide component between resistance and capacitance, and it was found that the device
was applicable to the selective detection of NO or NO2 concentration in each ingredient. Especially,
those using TiO2, SnO2 (n-type semiconductor) and perovskite-type oxides (LaCoO3, LaNiO3 and
LaCrO3) based receptors gave good responses to NO and NO2. It was also found that the responses
were different between n-type or p-type semiconductors, in which we tried to elucidate the sensing
mechanism
P1.6.1 Impedancemetric NOx Sensor Using YSZ-Based Solid Electrolyte Attached with Oxide Receptor