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

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.

Iron doped gold cluster nanomagnets: ab initio determination of barriers for demagnetization

“…The face substituted system is most stable, followed by the edge (0.25 eV higher) and corner (0.64 eV higher) substitutions. The same result is found in the study of Tam et al 12 In Table 2, we further list the relative energies of the NEVPT2 calculations, using (c)-CAS (11,10), which support the energetic order of the B3LYP calculations. For most systems however, NEVPT2 predicts slightly higher relative energies.…”

“…[2][3][4][5][6][7] Gold clusters usually exhibit small (S ¼ 0, 1/2) spin quantum numbers, leading to closed shell or doublet electronic ground states but doping them with a transition metal atom can lead to open-shell clusters with signicantly higher spin-quantum numbers. [8][9][10][11][12][13][14] For example, Tam et al 12 investigated the structure and stability of transition metal doped golden pyramids Au 19 M (M ¼ Cr, Mn, Fe) at the level of generalized gradient density functional theory (DFT). All systems show higher ground state spin quantum numbers, while the structural modications are minor.…”

“…15 Single molecule magnets (SMMs) can be seen as a special class of open-shell systems with distinct properties. For example, the rst investigated SMM, the dodecanuclear manganese acetate cluster [Mn 12 O 12 (CH 3 COO) 16 (H 2 O) 4 ]$2CH 3 -COOH$4H 2 O 16-18 exhibits a ground state spin quantum number of S ¼ 10 and can be magnetized by an external magnetic eld. Once the eld is switched off, the system relaxes via various channels back to the initial non-magnetized state.…”

“…Several studies have investigated transition metal doped gold clusters using DFT. [8][9][10][11][12][13][14] These studies focused on predicting stable structures and their spin quantum numbers. On the other hand, several studies examined magnetic properties of transition metal complexes, i.e., a transition metal ion surrounded by a primarily organic framework, with wave function based, multireference perturbation theory methods.…”

[M16Ni24(CO)40]4–: Coinage Metal Tetrahedral Superatoms as Useful Building Blocks Related to Pyramidal Au20 Clusters (M = Cu, Ag, Au). Electronic and Bonding Properties from Relativistic DFT Calculations

“…Its electronic structure, investigated by density functional calculations, [18][19][20][21][22][23] exhibits a large HOMO−LUMO energy gap, in agreement with its remarkable stability and unique optical and catalytic properties. 18,[24][25][26][27][28][29][30] Its structure is that of a bulk face-centered cubic (fcc) gold fragment, in a finite nanosized cluster motif. 18,26 Efforts to bring [Au 20 ] species into solution has been carried out since the last ten years, 26,[31][32][33][34][35] which resulted in structures and electronic structures completely different from that of the 37,38 was a first example of the capability of Group 11 cores to be embedded in an outer shell made of organometallic units, which can increase the versatility of the protecting layer.…”