Determination of the states of oxidation of metals in thin oxide films by X-ray photoelectron spectroscopy

The states of oxidation of molybdenum, tungsten, niobium, and tantalum in thin oxide films of variable composition were determined by X-ray photoelectron spectroscopy. It was found that the metals occurred in different states of oxidation in thin oxide films prepared by the irradiation of metal surfaces with low-energy oxygen ions under high-vacuum conditions. The concentrations of metals in different states of oxidation essentially depend on the radiation dose and the reactivity of metals.