Au19M (M=Cr, Mn, and Fe) as magnetic copies of the golden pyramid

Nguyen Minh Tam,Hung Tan Pham,Nguyen Thanh Tung,Ngo Tuan Cuong

doi:10.1038/s41598-017-16412-3

Nguyen Minh Tam, Hung Tan Pham + Show 2 more

Open Access

https://doi.org/10.1038/s41598-017-16412-3

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Abstract

An investigation on structure, stability, and magnetic properties of singly doped Au19M (M=Cr, Mn, and Fe) clusters is carried out by means of density functional theory calculations. The studied clusters prefer forming magnetic versions of the unique tetrahedral Au20. Stable sextet Au19Cr is identified as the least reactive species and can be qualified as a magnetic superatom. Analysis on cluster electronic structures shows that the competition between localized and delocalized electronic states governs the stability and magnetic properties of Au19M clusters.

Highlights

Last decades have witnessed an increasing interest in gold nano-clusters thanks to their precious catalytic, electronic, and optical properties[1,2,3]
Selective doping with Hf and Ge atoms has been applied to modify the catalytic activity of Au20 through transforming the cluster structure[54]
Singlet Au20 is found to be very stable in form of a tetrahedral with a calculated HOMO-LUMO energy gap of 1.80 eV, in an excellent agreement with the measured value (1.77 eV)[12]

Summary

Computational setup

The structural optimization of Au19M clusters have been carried out by density functional theory (DFT) calculations implemented in the Gaussian 09 software[55,56]. We used the BP86 functional in conjunction with basis sets cc-pvDZ-pp for Au and cc-pvDZ for Cr, Mn, and Fe. Possible structures of Au19M clusters were generated using a stochastic algorithm[57]. Isomers having relative energies within 2.0 eV were selected for recalculating single point energies at the same functional but combining with larger basis set, cc-pvTZ-pp for Au and cc-pvTZ for Cr, Mn, and Fe. In the following, we discuss the structural, stability, and magnetic aspects of the doped Au19M clusters. The selection of the BP86/cc-pvDZ-pp and cc-pvDZ functional resulted from test calculations for Au2, AuCr, AuMn, AuFe, Au2Cr+, and Au2Mn. The calculated results are presented, along with available computational and experimental data for comparison. We are confident that the used computational approach is suitable to describe the structures and properties of Au19M clusters

Results and Discussions

Conclusions

Additional Information