Growth of oxide-metal interfaces by atomic oxygen: Monolayer of NiO(001) on Ag(001)

We have tested the use of atomic oxygen to prepare $3d$ oxide-metal interfaces for which standard reactive deposition techniques based on molecular oxygen fail in providing well-defined chemical composition and controlled atomic structure and morphology. Using monolayer NiO(001) on Ag(001) as a model system, we find that NiO(001)/Ag(001) films grown by atomic oxygen have a two-dimensional highly stoichiometric $(1\ifmmode\times\else\texttimes\fi{}1)$ structure and a uniform monoatomic thickness, while those grown by conventional ${\text{O}}_{2}$ have a nonstoichiometric $(2\ifmmode\times\else\texttimes\fi{}1)$ structure or a three-dimensional morphology. Atomic oxygen may provide a practical way to prepare $3d$ oxide-metal interfaces with highly controlled stoichiometry, structure, and morphology.