Real-space observation of the reconstruction of Au(100)

We have investigated the reconstruction of the Au(100) surface with scanning tunneling microscopy. The measured corrugation pattern is described in detail by an isotropically contracted and slightly rotated, buckled hexagonal top layer, forming an incommensurate Au on Au structure. Contraction of atomic spacing is 3.82%, rotation 0.1°. The underlying cubic layer determines the vertical position of the top-layer atoms but its structure appears to have little or no influence on the contraction. The resulting interference pattern shows a dominant buckling of various 1× 5 corrugations arranged in an apparently large unit cell, which is approximately X 0 Z Y, where X = 24 ± 3, Y = 48 or 43, depending on temperature, and - 5 ≤ Z. ≤ 0. © 1984.