STRESS RELIEF IN RECONSTRUCTION

We report on the first direct measurement of the change of the surface stress in the reconstruction of the Au(111) and the Au(100) surfaces. For both surfaces the reconstruction relaxes the intrinsic tensile st ress, by 22% and 5%, respectively. A discussion of the data on the Au( 111) surface in the Frenkel-Kontorova model shows that the energy gain due to the surface stress is not quite large enough to make the recon structed phase energetically favored without the formation of the seco ndary herringbone structure of the solitons. On the Au(100) surface, t he gain in elastic strain energy is clearly insufficient to cause the surface to reconstruct.