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arXiv · 0708.1369

The effect of Fe atoms on the adsorption of a W atom on W(100) surface

J. Houze·Sungho Kim·Seong-Jin Park·Randall M. German·M. F. Horstemeyer·Seong-Gon Kim
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Abstract

We report a first-principles calculation that models the effect of iron (Fe) atoms on the adsorption of a tungsten (W) atom on W(100) surfaces. The adsorption of a W atom on a clean W(100) surface is compared with that of a W atom on a W(100) surface covered with a monolayer of Fe atoms. The total energy of the system is computed as the function of the height of the W adatom. Our result shows that the W atom first adsorbs on top of the Fe monolayer. Then the W atom can replace one of the Fe atoms through a path with a moderate energy barrier and reduce its energy further. This intermediate site makes the adsorption (and desorption) of W atoms a two-step process in the presence of Fe atoms and lowers the overall adsorption energy by nearly 2.4 eV. The Fe atoms also provide a surface for W atoms to adsorb facilitating the diffusion of W atoms. The combination of these two effects result in a much more efficient desorption and diffusion of W atoms in the presence of Fe atoms. Our result provides a fundamental mechanism that can explain the activated sintering of tungsten by Fe atoms.

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J. Houze, Sungho Kim, Seong-Jin Park, Randall M. German, M. F. Horstemeyer, Seong-Gon Kim. 2007-08-10. The effect of Fe atoms on the adsorption of a W atom on W(100) surface. https://doi.org/10.1063/1.2924411

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