STM study of the nanostructures prepared bydeposition of NiO on Ag(001)

Submonolayers of nickel oxide were grown on the Ag(001) surface by evaporation of Ni in the presence of O2 at a pressure of 1 × 10−6 mbar. In the early stages of deposition, two-dimensional oxide islands with a (2 × 1) periodicity grow on Ag(001). After annealing at about 500 K, the (2 × 1) single atomic layer transforms into NiO(001) double layer islands. The 1:1 stoichiometry of the film is not influenced by whether the annealing is carried out in vacuum or in the presence of oxygen. However, the oxide islands exhibit different morphologies depending on the O2 pressure during the annealing process.