Improved desorption temperature of magnesium hydride via multi-layering Mg/Fe thin film

Hydrogen sorption property of Mg in Pd-capped thin film nanoconfined with Fe is investigated. Two methods of depositing the thin films were utilised, i.e., resistive heating method and pulsed laser deposition (PLD) method. In the thinnest Mg film prepared by resistive heating, hydrogen content was observed to be the highest among all samples and the hydrogen desorption temperature is 230 °C. Using pulsed laser deposition method, Mg/Fe nanoconfined multilayers are easily prepared. The hydrogen desorption temperature of Mg film with 12 Mg/Fe layers prepared via PLD method was significantly reduced to 155 °C, and the hydrogen storage capacity is improved as compared to the Mg/Fe with only several layers of same overall thickness. This study showed that the desorption temperatures correlate with the film thickness, thinner films react with hydrogen at lower temperatures. In addition, multi-layering Mg with Fe improves the desorption temperatures and hydrogen capacity, due to the higher grain boundary density, which acts as diffusion pathways for Pd in hydrogenation and dehydrogenation process.