Electrical resistance change due to hydrogenation of Pd and Pd-Ni thin films immersed in hydrogen-dissolved water

The Pd and Pd-Ni thin films with an fee structure were prepared by sputtering. The films were immersed in the pure water and the hydrogen-dissolved water alternatively and the electrical resistance of the films was measured during the immersion. The Pd and Pd-Ni thin films possess good sensitivity to hydrogen dissolved in water. The electrical resistance of the films increases in the hydrogen-dissolved water and decreases in the pure water with excellent reproducibility. The electrical resistance change of the Pd-Ni alloy films is smaller than that of the Pd films. Nickel addition improves the response of increase/decrease of the electrical resistance during the immersion in the pure water and the hydrogen-dissolved water. The detailed electrical behavior of the films is investigated in this study.