Open AccessAtomic Hydrogen Diffusion in Novel Magnesium Nanostructures: The Impact of Incorporated Subsurface Carbon Atoms
Author(s) -
Aijun Du,
Sean C. Smith,
Xiangdong Yao,
Yinghe He,
Gao Qing Lu
Publication year - 2006
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/29/1/032
Subject(s) - magnesium , hydrogen , diffusion , materials science , nanostructure , carbon fibers , chemical physics , nanotechnology , atomic physics , chemical engineering , inorganic chemistry , chemistry , metallurgy , physics , thermodynamics , composite material , organic chemistry , composite number , engineering
Ab initio Density Functional Theory (DFT) calculations are performed to study the diffusion of atomic hydrogen on a Mg(0001) surface and their migration into the subsurface layers. A carbon atom located initially on a Mg(0001) surface can migrate into the sub-surface layer and occupy a fcc site, with charge transfer to the C atom from neighboring Mg atoms. The cluster of postively charged Mg atoms surrounding a sub-surface C is then shown to facilitate the dissociative chemisorption of molecular hydrogen on the Mg(0001) surface, and the surface migration and subsequent diffusion into the subsurface of atomic hydrogen. This helps rationalize the experimentally-observed improvement in absorption kinetics of H2 when graphite or single walled carbon nanotubes (SWCNT) are introduced into the Mg powder during ball millingNo Full Tex