MgNi/Pd multilayer hydrogen storage thin films prepared by dc magnetron sputtering

Abstract

MgNi/Pd multilayer thin films were deposited on Ni substrate by direct current (dc) magnetron sputtering using a dual-target, each MgNi layer being 40 nm and each Pd layer being 16 nm in thickness. The total thickness of the MgNi/Pd multilayer thin film is about 1.7 μm. X-ray diffraction and scanning electron microscopy analysis revealed that the microstructure of the MgNi layer is amorphous and/or nanocrystalline and that the microstructure of the Pd layer is fine grained crystalline with no preferential orientation. A pressure–composition–isotherm (PCI) measurement of films proved that the hydrogen absorption content reached to 4.6 mass% at room temperature and hydrogen desorption reached 3.4 mass% hydrogen. The deposited MgNi/Pd multilayer thin films show an interesting behavior of discharge capacity with a maximal value of 505 mAh/g.