Formation of ordered islands in CO adsorption on K pre-covered Ni(100) surfaces

Coadsorption of CO on a K pre-covered Ni(100) surface leads to the formation of small ordered KCO islands. evidenced by scanning tunnelling microscopy. Structural models of these islands are presented, consistent with these and previous results. In a recent study of this system by Christensen and Nørskov, two configurational ‘strategies’ (I and II) were employed within an electrostatic framework to model microcalorimetry data. These STM findings clearly support this electrostatic model and favour the rearrangement of K atoms adopted in strategy II, but with limited K diffusion.