Efficient growth of ordered thin oxide films on Ni(1 1 1) by NO2 oxidation

The efficient growth of ordered thin oxide films on Ni(1 1 1) using low NO2 gas exposures under ultrahigh vacuum conditions has been achieved. The reaction mechanism of NO2 on Ni(1 1 1) at 500–600 K changes from total decomposition to partial dissociation into NO and O after a critical surface adatom coverage has been attained. Auger electron spectroscopy (AES) and low energy electron diffraction (LEED) reveal the creation of an intermediate NiO(1 0 0) phase, followed by the eventual formation of clean NiO(1 1 1) overlayers. Reflection absorption infrared spectroscopy (RAIRS) using CO molecules as probes of the surface adsorption sites present confirms the conversion of Ni0 to Ni2+ during the oxidation process.