| 摘要 |
PURPOSE:To prevent the diffusion of a catalyst into a metal oxide film to obtain a gas detecting element having high sensitivity and free from change with the elapse of time, by arranging a detection part formed by providing a metal oxide thin film on an insulating substrate and a catalyst part provided on a separate insulating substrate in opposed relation to each other so as to leave the gap therebetween. CONSTITUTION:A metal oxide thin film 3 is formed on an insulating substrate 2 such as a quartz glass substrate and electrodes 4 comprising Pt are formed to both sides of the film 3 to form a gas detecting part 1. On the other hand, Pt or Pd is subjected to sputtering to form a catalyst layer 5 on a separate quartz glass substrate 6 and the film 3 and the layer 5 are opposed while Pt wires 7 are inserted so as to be contacted with the electrodes 4, 4 and the ends of the layer 5 and the substrate 6 to obtain a gas detecting element wherein the film 3 and the layer 5 are slightly spaced apart. Especially, when stock material comprising a powder mixture of Fe2O3 containing 0.1-10mol% of either one of TiO2 or WO3 is sputtered to the film, the element having high sensitivity to CH4 gas is obtained. |
