A New Model for the Cleaved Si (111)-(2x1) Surface
There is currently general agreement about the structures of Si(100) and annealed Si(111) (7×7) surfaces, but the situation for the cleaved Si(111) (2×1) surface is less satisfactory . A Si crystal in the (111) orientation can be viewed as a series of tetrahedra with one bond vertical and the other three forming the base, resulting in a structure that consists of double layers of closely spaced atomic planes (d = 0.78 Å) separated from each other by the Si interatomic distance d = 2.35 Å. All of the existing models use as their basis the assumption that in cleavage, the one bond that is oriented normal to the (111) surface breaks, so that the termination is the closely-spaced-layer pair that then reconstructs to form the (2×1) surface.
KeywordsNickel Catalysis Hexagonal Azimuth Smit
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