The structural, electronic and magnetic properties of Ag₄M and Ag₄MCO (M = Sc–Zn) clusters

Abstract

The structures, spectra and electronic and magnetic properties of Ag₄M and Ag₄MCO (M = Sc–Zn) clusters have been studied using density functional theory and CALYPSO structure searching method. Structural searches show that M atoms except Zn tend to occupy the highest coordination position in the ground state Ag₄M and Ag₄MCO clusters. Carbon monoxide is most easily adsorbed on Ag atom of Ag₄Zn and M atom of other Ag₄M. Infrared and Raman spectra, photoabsorption spectra and photoelectron spectra of Ag₄M and Ag₄MCO clusters are forecasted and can be used to identify these clusters from experiment. Analysis of electronic properties indicates that the adsorption of CO on Ag₄M clusters changes the zero vibrational energy (ZPVE) and increases stability of the host clusters. Dopant atoms except for Zn improve the stability of silver cluster. The Ag₄Ni cluster shows high chemical activity and maximum adsorption energy for carbon monoxide. Magnetism calculations reveal that the magnetic moment of Ag₄M (M = Mn–Ni) cluster adsorbed by carbon monoxide is decreased by 2 μ_B. The change of magnetic moment makes it possible to be used as a nanomaterial for carbon monoxide detection. Simultaneously, it is found that the adsorption of CO on Ag₄Cu cluster is a physical adsorption.

GRAPHICAL ABSTRACT

KEYWORDS:

• Structure
• spectrum
• stability
• chemical activity
• magnetic moment

Additional information

Funding

This project was supported by the Chunhui Plan of the Ministry of Education of China (grant no.: Z2017090) and by the Education Department of Sichuan Province (grant no.: 172481).