Atomic-Scale Distribution of Water Molecules at the Mica-Water Interface Visualized by Three-Dimensional Scanning Force Microscopy

We have developed a method referred to as three-dimensional scanning force microscopy (3D-SFM) which enables us to visualize water distribution at a solid-liquid inter-face with an atomic-scale resolution in less than 1 min. The 3D-SFM image obtained at a mica-water interface visualizes 3D distributions of adsorbed water molecules above the center of hexagonal cavities and the laterally distributed hydration layer. The atomically resolved 3D-SFM image showing mirror symmetry suggests the existence of surface relaxation of the cleaved mica surface next to the aqueous environment.