Mg:Nb films produced by pulsed laser deposition for hydrogen storage

Magnesium thin films with controlled Nb content (Mg:Nb) were deposited by pulsed laser deposition (PLD) in a single step process using a composite target consisting on separate zones of matrix (Mg) and alloying element (Nb). Scanning electron microscopy (SEM) analysis showed a double structure of the thin film samples consisting on a homogeneous thin film ∼1 μm thick and large Mg:Nb spheres with dimensions ranging from ∼1 μm for energy density of the laser pulse lower than 10 J/cm2 to ∼10 μm for higher energy, 30–40 J/cm2. The crystalline structure of the deposited samples consisted of (0 0 1) oriented Mg layers with Nb atomically dispersed in the Mg structure or in form of nanoclusters. A preliminary test on the hydrogen absorption capacity of the PLD deposited samples was carried out by thermal desorption spectroscopy (TDS).