Interaction Energy and Configuration of Ledges on (001) Copper Surfaces
A computer model of the surface, consisting of a crystal with (001) terraces and either one or two ledges, has been constructed. Interaction between the atoms of the model has been described by means of a Morse potential. Given this force law and a previously developed zero-force atomic relaxation technique, it has been possible to establish the configuration of an isolated ledge, the attendant displacement field as well as the increase in energy which results upon introduction of a ledge on an otherwise perfect surface.
Consideration of surfaces with two ledges has allowed computation of the interaction between all three types of ledge pairs, as a function of ledge spacing. The results obtained show that the interaction between the displacement fields of a pair of ledges is short range and repulsive in all cases.
Estimates of the anisotropy of surface energy, on the basis of the calculated interaction, are found to agree qualitatively with the trends observed experimentally at high temperatures. When the present results are combined with a suitable high-temperature model, they are found to provide a correction in the proper direction.
KeywordsInteraction Energy Displacement Field Copper Surface Morse Potential Absolute Zero
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- 1.Robertson, W. M., and Shewmon, P. G., Trans. Met. Soc. AIME, 224: 804 (1962).Google Scholar
- 3.Hirth, J. P.,in “Energetics in Metallurgical Phenomena”, W. M. Mueller (ed.), Vol II, p. 1, Gordon and Breach, New York, 1965.Google Scholar
- 4.Mullins, W. W., ASM Seminar on “Metal Surfaces”, p. 17, ASM, Metals Park, 1962.Google Scholar
- 5.Blakely, J. M., and Schwoebel, R. L., to be published in Surface Science.Google Scholar
- 12.Hondros, E. D., and McLean, M., “Structure et Proprietes des Surfaces Solides”, p. 219, Editions du Centre National de la Recherche Scientifique, Paris, 1970.Google Scholar