Response characteristics to reducing gases in BaTiO3-based thick films

The added graphite formed interstitial solid solutions with Ba0.999Sb0.001TiO3 and did not cause any modification in the crystalline structure. The sintered bodies of the BaTiO3-based thick films showed a tetragonal perovskite structure. The response characteristics of the electrical resistivity for the BaTiO3-based thick films to reducing gases such as CH4, N2 and CO were studied. The electrical resistivities below the Curie temperature (∼120 °C) in all the atmospheres were nearly the same irrespective of atmospheres. However, the electrical resistivities at high temperatures (>∼150 °C) strongly depended on the atmosphere. The response characteristics of the electrical resistivity to reducing gases followed the order of CO > CH4 > N2. The discrepancy in the resistivities measured at high temperatures in air and reducing gases became remarkable with increases in graphite contents.