Adsorption and Diffusion of Hydrogen on Low-Index (110) and (111) Surfaces of Aluminum

Autor: T. N. Genarova, A. L. Zaitsev
Rok vydání: 2018
Předmět:
Zdroj: Journal of Engineering Physics and Thermophysics. 91:1603-1616
ISSN: 1573-871X
1062-0125
DOI: 10.1007/s10891-018-1899-4
Popis: By the density-functional method, the authors have considered the energetics of adsorption and diffusion of a hydrogen molecule into atomically thin aluminum plates with body-centered tetragonal and rhombohedral crystallite structures bounded by the (110) and (111) surfaces, and also geometric configurations of surface aluminum hydrides. It has been shown that physical adsorption of H2 molecules on the Al(110) and Al(111) surfaces is a weak exothermic process. Polarization and deformation due to the physical adsorption lead to a certain increase in the H–H interatomic spacing (0.734 A). The diffusion of the hydrogen atoms into body-centered tetragonal and rhombohedral plates tends to increase the system's energy. It has been found that hydrogen diffuses most easily through the Al(110) surface; in atomic diffusion through the subsurface layer, the energy grows up to 1.1 eV. A stable energy state is attained due to the formation of a tetrahedral hydrogen complex.
Databáze: OpenAIRE