Abstract
A new combustible gas sensor using porous nickel ferrite (NiFe2O4) was fabricated to investigate its gas sensing characteristics. After fine nickel ferrite powder was mixed with camphor powder and then pressed into disks, they were sintered at the range from 1, 200 to 1, 400°C for 2h in air. The optimum sintering temperature and the optimum mixing ratio of nickel ferrite to camphor were found to be 1, 200°C and 1:1, respectively. The gas sensor fabricated under these conditions, with a porosity of 83.7%, had significant sensitivity to hydrogen and saturated hydrocarbon gases. The addition of a small amount of noble metals (Pt, Au, Pd) to the porous nickel ferrite disks also influenced the gas sensitivity. Addition of Pt was effective to increase the sensitivity to hydrogen gas.
