PHASE-BEHAVIOR OF THE AU(111) SURFACE - DISCOMMENSURATIONS AND KINKS

The clean Au(111) surface is found, using x-ray diffraction, to reconstruct between 300 and 1250 K with two distinct phases. Below 865 K, the surface structure consists of an equilibrium density of kinks between rotationally equivalent domains, each of which is itself composed of a sequence of uniaxial discommensurations. Above 880 K, the arrangement of kinks and discommensurations is disordered, which results in an isotropic compression of the reconstructed layer. The phase transition between the two structures is first order.