Geometrical, electronic, and magnetic properties of small Au_nSc (n=1–8) clusters

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• 作者：Die Dong^a ; ^b ; ^{science_dd@163.com"" rel=""nofollow} ; Kuang Xiao-Yu^b ; ^c ; Zhu Bing^a ; Guo Jian-Jun^a
• 关键词：Au_nSc cluster ; Geometrical structure ; Electronic and magnetic property
• 刊名：Physica B
• 出版年：2011
• 出版时间：1 September 2011
• 年：2011
• 卷：406
• 期：17
• 页码：3160-3165
• 全文大小：910 K

文摘

Geometrical, electronic, and magnetic properties of the Sc-doped gold clusters, Au_nSc (n=1–8), have been studied using the density-functional theory within the generalized gradient approximation. An extensive structural search shows that the Sc atom in low-energy Au_nSc isomers tends to occupy the most highly coordinated position. The substitution of a Sc atom for an Au atom in the Au_n+1 cluster markedly changes the structure of the host cluster. Moreover, we confirm that the ground-state Au₆Sc cluster has a distortion to a lower D_2h symmetry. The relative stabilities and electronic properties of the lowest-energy Au_nSc clusters are analyzed based on the averaged binding energies, second-order energy differences, fragmentation energies, chemical hardnesses, and HOMO–LUMO gaps. It is found that the magic Au₃Sc cluster can be perceived as a superatom with high chemical stability and its HOMO–LUMO gap is larger than that of the closed-shell Zr@Au₁₄ cluster. The high symmetry and spin multiplicity of the Au₃Sc and Au₆Sc clusters are responsible for their large vertical ionization potential and electron affinity. The magnetism calculations indicate that the magnetic moment of the Sc atom in the ground-state Au_nSc (n=2–8) clusters gradually decreases for even n and is completely quenched for odd n.