Evolution of Electronic Properties of Tantalum Nanoclusters and of Tantalum Oxides in the Vicinity of Phase Transition to the Nonconducting State

Core–shell samples of thin films of tantalum nanoclusters and of tantalum oxides on silicon were obtained. The chemical composition of Ta/TaO2 nanoclusters was determined based on the results of X-ray photoelectron spectroscopic (XPS) analysis. The homogeneity of the thin nanocluster film composition was ascertained by the character of angular dependences of the ratios of the Ta4f doublet and oxygen peaks. The effect of a dimensional shift of binding energy was observed for metal tantalum nanoclusters with the diameter d < 5 nm, and its dependence on the nanocluster diameter was established.