Nucleation and growth of a monolayer oxide on Cu(110)

The process of oxygen chemisorption on a Cu(110) surface has been observed dynamically using scanning tunneling microscopy. The chemisorbed oxygen was found to nucleate on terraces, and not at step edges. Isolated chains grow along the 〈001〉 by homogeneous nucleation. The driving force for the growth is a repulsive interaction along the 〈110〉 and an attractive interaction along the 〈001〉 between 0 atoms.