A theory of the surface reconstruction in gold

A phenomenological theory of the unidirectional contraction of the (111) surface layer of gold at low temperatures and the isotropic contraction of it at high temperatures is presented. It is shown that the state contracted unidirectionally in one of the 〈1$\text{1}$0〉 directions is of lowest energy in an intermediate range of the magnitude of the misfit energy, being stabilized mainly by the elastic energy λe_xxe_yy of the two dimensional continuum model. The reconstruction of the (100) surface is also discussed.