Lu, GangOrlikowski, DanielPark, IckjinPolitano, OlivierKaxiras, Efthimios2019-09-202002Lu, Gang, Daniel Orlikowski, Ickjin Park, Olivier Politano, and Efthimios Kaxiras. 2002. “Energetics of Hydrogen Impurities in Aluminum and Their Effect on Mechanical Properties.” Physical Review B 65 (6). https://doi.org/10.1103/physrevb.65.064102.1098-01211550-235Xhttp://nrs.harvard.edu/urn-3:HUL.InstRepos:41384083The effects of hydrogen impurities in the bulk and on the surface of aluminum are theoretically investigated. Within the framework of density-functional theory, we have obtained the dependence on 14 concentration of the stacking fault energy, the cleavage energy, the Al/H surface energy, and the Al/H/Al interface formation energy. The results indicate a strong dependence of the slip energy barrier in the [(2) over bar 11] direction, the cleavage energy in the [111] direction and the Al/H/Al interface formation energy, on H concentration and on tension. The dependence of the Al/H surface energy on H coverage is less pronounced, while the optimal H coverage is less than or equal to0.25 ML. The calculated activation energy for diffusion between high-symmetry sites in the bulk and on the surface is practically the same, 0.167 eV. From these results, we draw conclusions about the possible effect of H impurities on mechanical properties and, in particular, on their role in ernbrittlement of Al.en-USJournal Article2019-09-2010.1103/PhysRevB.65.064102