Growth mode of NiO on Cu(111) studied using scanning tunneling microscopy and surface x-ray diffraction

Abstract

A microscopic description, coherently describing morphological, spectroscopic, and diffraction measurements, of the interface formed by room-temperature deposition of ultrathin nickel oxide layers on a Cu(111) single crystal is presented. The morphology of the Cu(111) substrate surface with respect to the NiO thickness shows a specific hole formation attributed to an oxygen promoted diffusion of Cu on the Cu(111) surface combined with Ni diffusion. It is shown that nickel is dissociated from oxygen in the early stages of growth (below 6 \AA{}) and that nickel diffuses inside the two first sublayers of Cu(111) whereas O atoms form an adsorbed overlayer.