Origin of the core-level binding energy shifts in Au nanoclusters

Abstract

We investigate the shifts of the core-level binding energies in small gold nanoclusters by using ab initio density-functional-theory calculations. The shift of the 4f states is calculated for magic-number nanoclusters in a wide range of sizes and morphologies. We find a nonmonotonous behavior of the core-level shift in nanoclusters depending on the size. We demonstrate that there are three main contributions to the Au 4f shifts, which depend sensitively on the interatomic distances, coordination, and quantum confinement. They are identified and explained by the change of the on-site electrostatic potential.<p>Funding Agencies|Knut and Alice Wallenberg Foundation [2012.0083]; Strong Field Physics and New States of Matter (COTXS); Ministry of Education and Science of the Russian Federation [14.Y26.31.0005]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009 00971]</p

Correlation between Ethylene Adsorption Energies and Core-Level Shifts for Pd Nanoclusters

“…According to the d-band model, the difference of adsorption energies on transition metals in different environments can be determined by the location of the d-band center with respect to the Fermi energy. In a previous work, it was shown that CLS in nanoclusters correlate with differences in d-band centers . This is understandable as the d-band center shifts, similar to the shifts of the core-state eigenvalues, are determined by the shift of the electrostatic potential.…”

“…The analysis of CLS in small nanoclusters presented in ref suggests that the final-state effects partially compensate for the initial-state shift (see eq ), typically decreasing the absolute value of the shift. Nevertheless, the effect of the core-hole screening is rather modest and similar for different sizes and structures.…”

“…For example, the generalized coordination number accounts for the number of neighbors with their coordinations. However, as exemplified in ref , the size evolution of electronic properties of small nanoclusters is nonmonotonous and highly sensitive to confinement effects and local strains. , Thus, the shifts of the valence band, core states, and adsorption energy can generally not be fully described by descriptors that explicitly do not account for such effects. In Figure , the correlation between adsorption energy and GCN is shown.…”

“…Density functional theory (DFT) calculations have shown to accurately reproduce measured core-level shifts (CLS) for the adsorption of simple adsorbates on metal surfaces. , Recent works also include metal NCs, , and in ref , it was shown how confinement effects, local coordination, and interatomic distances affect the 4f CLS for bare Au NC. As yet, however, the dependence of CLS on adsorption energies has not been comprehensively investigated for metal NCs.…”

Electronic Structure and Bond Relaxation at Na/Ta(110) Interfaces and 1D‐Chain and 2D‐Ring Ta Metal Structures on Na(110)

“…Energy shifts of surface atoms have been observed in defect generations, alloy formations, and chemisorption systems. For example Alexey A. Tal et al studied energy shifts in Au nanoclusters . William E. Kaden et al studied energy shifts of Pd atoms adsorbed on ultrathin SiO 2 films .…”