Ordered array and motion of water molecules and ions at the interface between KBr(c)/NaCl(c) and water

The atomic-resolution images at the terrace of KBr(c)/NaCl(c) surface covered with water have been observed using an atomic-force microscope. The direct observation of the vertical motion of cations as well as the water-molecules ordered array at the interface was for the first time demonstrated in the atomic-resolution AFM image. The observed water molecules bridge each bromide ion-pair and are sandwiched between the potassium ions at the higher level right on the underlying bromide ions.