title: Nucleation and growth mechanisms of nano magnesium hydride from the hydrogen sorption kinetics.
abstract: We use a combination of hydrogenography and Johnson-Mehl-Avrami-Kolmogorov (JMAK) analyses to identify (1) the driving force dependence of the nucleation and growth mechanism of MgH2 in thin film multilayers of Mg (10 nm) and (2) the nucleation and growth mechanism of Mg in the earlier formed MgH2, i.e. the hydrogen desorption process. We conclude that JMAK may be successfully applied to obtain the nucleation and growth mechanism of hydrogen absorption. The desorption mechanism, however, is not simply the reverse of the absorption mechanism. We find evidence that the barrier for nucleation of Mg is small. The dehydrogenation probably involves the formation of voids, which is energetically more favorable than elastic and plastic deformation of the multilayer.
authors.affiliation: Department of Chemical Engineering, Delft University of Technology, Julianalaan 136, 2628BL, Delft, The Netherlands. lpamooij@gmail.com
authors.forename: Lennard
authors.initials: L
authors.lastname: Mooij
authors.forename: Bernard
authors.initials: B
authors.lastname: Dam
mesh_terms: D000327:Adsorption; D006859:Hydrogen / Q000737:chemistry; D007700:Kinetics; D008274:Magnesium / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D006859:Hydrogen; D008274:Magnesium