Limiting current-type gas sensor using a high temperature-type proton conductor thin film

A limiting current-type gas sensor was composed using a thin film of the high temperature type proton conductor, CaZr0.9In0.1O3-a. The perovskite structure film nas obtained by sputtering in Ar and a heat-treatment at 900 degrees C in air. A hydrogen concentration cell with this film showed theoretical EMF's at the temperatures from 500 degrees C to 700 degrees C. Therefore this fill was regarded as a proton conductor. The film also showed a conductivity of 7 x 10(-5) S cm(-1) at 700 degrees C in hydrogen atmosphere. The limiting current type gas sensor was composed by laminating Pt films and the proton conductor film on a alumina porous substrate. The sensor showed limiting current characteristic corresponding to partial pressures of H-2, C3H8 and CO. relationship was obtained between the limiting current and partial pressure of these gases.