Revealing of the new freedom of size: atomic energy levels, screening and charge transporting

TL;DR

This paper explores how miniaturization affects atomic energy levels, screening, and charge transport, providing a new way to understand and calibrate the physical properties of nanomaterials through spectral analysis.

Contribution

It introduces a size-dependent analysis method using bond order-length-strength correlation to quantify energy level shifts in nanoparticles, distinguishing screening effects from valence recharging.

Findings

Quantitative energy level shifts in Cu nanoparticles were determined.

Discrimination between screening effects and valence recharging was achieved.

Size dependence of Auger spectra was characterized.

Abstract

Miniaturization of a solid forms a new freedom that is fascinating, which allows us not only to tune the physical properties of a solid but also enables us to gain information about the energy levels of an isolated atom and the effect of screening and charge transporting in reaction on the energy level shift, a calibration of crystal binding. Incorporating the recent bond order-length-strength correlation mechanism [Sun, Phys. Rev. B 69, 045105 (2004)] to the size dependence of Auger photoelectron coincidence spectra of Cu nanoparticles with and without being passivated has enabled us to gain quantitative information about the 2p and 3d level energies of an isolated Cu atom and their shift upon bulk formation. The developed approach also enabled us to discriminate the effect of crystal-field screening from the effect of valence recharging (due to surface passivation and substrate-particle interaction) on the binding energies to the electrons at different energy levels of a specimen.