New hydrogen sensor based on sputtered Mg–Ni alloy thin film

Pd-capped magnesium–nickel alloy thin films were prepared by magnetron sputtering and their hydrogen sensing properties were investigated. By monitoring the resistance change or the transmittance change of the film, we can obtain the information on hydrogen concentration in air. The sensing range of this sensor is quite wide and it can measure the hydrogen concentration range from 10 ppm to 10% without heating. Using a certain protective coating, the durability of the film can be much improved. Also there is a unique application of Pd/Mg–Ni thin film as ‘hydrogen check sheet’, which can visualize the hydrogen flow.