Abstract
The roughening transition in the (110) faces of Ni, Cu, Pd and Ag is described in terms of the creation of anisotropic defects similar to the missing rows appearing in the reconstruction of Ir, Pt and Au. This picture is mapped onto an anisotropic version of the exactly solved 6-vertex model. From the latter the scattering intensities of both He atoms and X-rays are calculated, and compared with recent data on Cu and Ag(110).