Structural, electronic and magnetic properties of gold cluster doped with calcium: Au_nCa (n = 1–8)

Abstract

The geometrical structures, relative stabilities, electronic and magnetic properties of calcium-doped gold clusters Au _n Ca (n = 1–8) have been systematically investigated by employing density functional method at the BP86 level. The optimised geometries show that the ground-state structures are planar structures for Au _n Ca (n = 3–8) clusters. Ca-substituted Au _{n +1} clusters, as well as Au-capped Au _{n −1}Ca clusters, are dominant growth patterns for the Au _n Ca clusters. The relative stabilities of Au _n Ca clusters for the ground-state structures are analysed based on the averaged binding energies, fragmentation energies and second-order difference of energies. The calculated results reveal that the Au₂Ca isomer is the most stable structure for small size Au _n Ca (n = 1–8) clusters. The HOMO-LUMO energy gaps as a function of the cluster size exhibit a pronounced even–odd alternation phenomenon. Subsequently, charge transfers and magnetic moment of Au _n Ca (n = 1–8) clusters have been analysed further.

Keywords:

• Au _n Ca clusters
• geometrical configuration
• density function method

Acknowledgments

The authors are grateful to the National Natural Science Foundation of China (Nos. 10774103 and 10974138).