A study of many-body phenomena in metal nanoclusters (Au, Cu) close to their transition to the nonmetallic state

The results of a study of many-body phenomena in gold and copper nanoclusters are presented. The measured conductivity as a function of nanocluster height h was found to have a minimum at h ≈ 0.6 nm. Conductivity was local in character at nanocluster sizes l ≤ l _c ≈ 2.5 nm. Changes in core hole screening and an anomalous increase in the Anderson singularity index α in gold and copper nanoclusters could be caused by changes in permittivity from metallic (? → ∞) to nonmetallic (? ∝ l ²). The many-body phenomenon characteristics observed in the X-ray photoelectron and tunnel spectra of gold and copper nanoclusters as the size of the nanoclusters changed led us to suggest changes in the band structure of the nanoclusters and, therefore, their possible transition from the metallic to nonmetallic state.