DFT investigation of Au9M2+ nanoclusters (M = Sc-Ni): The magnetic superatomic behavior of Au9Cr2

• Published in: Chemical physics letters 2022-04, Vol.793, p.139451, Article 139451
• Main Authors: Lan, Ngo Thi, Mai, Nguyen Thi, La, Duong Duc, Tam, Nguyen Minh, Ngo, Son Tung, Cuong, Ngo Tuan, Dang, Nguyen Van, Phung, Thu Thi, Tung, Nguyen Thanh
• Format: Article
• Language: English
• Subjects: Density functional theory; Gold clusters; Superatoms; Transition metal clusters
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2022.139451

Binding energy per atom (BE) of Au9M2+ clusters and AuM dimers normalized with those of Au102+ and Au2, respectively. Au9Sc2+ and Au9Ti2+ prefer the type-I (endohedral cage-like) structure, while Au9M2+ (M = V, Cr, Mn, Fe, Co, and Ni) favor the type-II (tetrahedral) one. [Display omitted] •The structural evolution of Au9M2+ is ruled by the bond strength of AuM dimers.•The cage-like structure for M = Sc and Ti and the tetrahedral structure for heavier ones.•The exceptionally stable Au9Cr2+ is identified as a potential magnetic superatom. Au102+ has been found very stable showing a superatomic behavior with a highly symmetrical geometry and can be considered as the smallest copy of the golden pyramid Au20. In this work, we further explore superatomic clusters as analogues of more complex molecules by doping Au102+ cluster with 3d transition metal atom. It is found that, in similarity to their sister Au19M, the structural evolution of Au9M2+ is ruled by the bond strength of AuM dimers and can be generalized into two motifs: the endohedrally doped cage-like structure for lighter dopants (M = Sc and Ti) and the slightly distorted tetrahedral structure for heavier ones. The average binding energies and dissociation energies are calculated to identify the relatively stable patterns. The molecular orbital (MO) diagram as well as the spin distribution are computed to understand the electronic structure and magnetic behavior of studied clusters. The spin magnetic moments of Au9M2+ clusters systematically vary from 0 to 5 μB, depending on the localization of unpaired 3d electrons. With a large spin magnetic moment of 5 μB, the exceptionally stable Au9Cr2+ is identified as a potential magnetic superatom and would be beneficial for further theoretical and experimental studies.