Shear displacement of the K(110) surface

Abstract

A low-energy electron diffraction analysis of the clean K(110) surface has been performed at 25 K, providing a quantitative structural determination of a clean alkali-metal surface. The K(110) surface exhibits a novel surface phase consisting of a lateral shear displacement between the first two surface planes while preserving their two-dimensional periodicity. The atomistic description of this surface structure is related to that of the bulk martensitic phase transitions of the alkali metals.