Analysis of the Tight-Binding Description of the Structure of Metallic 2D Systems
Bidimensional metallic systems as interfaces, quantum wells and superlattices with sharp interfaces became recently available and their properties can now be experimentally studied in detail: To calculate the Local density of States (LDOS) for surfaces, interfaces, quantum wells and superlattices we use empirical tight-binding hamiltonians together with the Green function matching method (GFM). In this paper we show some examples of our results employing the method just outlined to describe metallic 2D systems. In particular, we refer briefly to the effect on the LDOS of the very recently established contraction of the first interatomic layer distance in the Ta(OOl) surface. We then discuss the Nb-V ideal (100) interface and conclude that under certain conditions the V-side of an interf ace can show magnetism as the V(001) surface does. As a last example, we present a calculation that relates the changes with gold coverage of the reaction rate of the catalytic reaction of cyclohexene into benzene on a Pt(001) surface to the changes on the LDOS of the outermost Pt atomic layer. We show that the behavior of the LDOS around the Fermi level is an important factor to the explanation of the behavior of this catalytic reaction. We conclude by stating that the empirical tight-binding method is a very simple and useful tool for the description of 2D metallic systems. The advantage is that the computational demands are low and all the ingredients to take full profit of this method are available (reliable tight-binding parameters and suitable methods f or the calculation of the Green function.).
KeywordsFermi Level Green Function Atomic Layer Gold Layer Sharp Interface
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