Hydrogenation of Pd capped Mg thin films at room temperature

Pd capped pure Mg thin films were prepared by DC magnetron sputtering and their hydrogenation at room temperature has been investigated. After exposure to 4% hydrogen gas diluted by argon, the Pd/Mg thin films on Si substrates at 295 K show drastic optical changes in reflectance within 5 s. XPS analysis reveals that there exists an intermixing layer of Pd and Mg near the surface, and MgH2 is formed very quickly in this intermixing layer. It is very interesting that such a fast hydrogenation occurs at room temperature.