Missing-row surface reconstruction of Ag(110) induced by potassium adsorption

We report a medium-energy ion-scattering study of the (1×2) reconstruction of the Ag(110) surface induced by submonolayer amounts of K. A qualitative comparison between ion-scattering data from the clean and K-covered surfaces shows that the (1×2) periodicity is caused by a missing-row reconstruction of the Ag substrate. Computer simulations support this conclusion and provide detailed information on the atomic positions. Our observations support a recent model by Heine and Marks explaining surface relaxation and reconstruction in terms of the occupation of s-p and d electronic levels.