The effects of Ni and Mg2Ni interlayer on hydrogenation properties of Pd sandwiched Mg films

The scope of present study is to investigate and compare the areal hydrogen concentration of Pd/Mg/Ni/Pd and Pd/Mg/Mg2Ni/Pd films with the Pd/Mg/Pd base system using Elastic Recoil Detection Analysis (ERDA) technique. Metals were deposited on Si substrate by thermal evaporation and electron gun evaporation technique followed by hydrogenation for 2 h at 150 degrees C and 2 bar hydrogen pressure. ERDA study reveals that Pd/Mg/Ni/Pd and Pd/Mg/Mg2Ni/Pd films absorb 7.08 x 10(17) and 1.68 x 10(18) hydrogen atoms/cm(2), respectively, in comparison to 4 x 10(17) atoms/cm(2) absorbed by base system. The influence of Ni and Mg2Ni interlayer on the hydrogen storage properties of base system were investigated by changes in structural and surface topographical properties using XRD and AFM techniques, respectively. These results strongly supports the ERDA findings, clearly shows that the addition of Ni or Mg2Ni layers to base system enhances its hydrogenation and decreases the oxygen content. The high hydrogen content in Mg/Mg2Ni bilayer can be explained by the formation of MgH2 and Mg2NiH4 phases. (C) 2010 Elsevier B.V. All rights reserved.