Electronic structure of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi mathvariant="normal">Mn</mml:mi><mml:mn>12</mml:mn></mml:msub></mml:math>derivatives on the clean and functionalized Au surface

Voss, Sönke; Fonin, Mikhail; Rüdiger, Ulrich; Burgert, Michael; Groth, Ulrich; Dedkov, Yuriy

doi:10.1103/physrevb.75.045102

Cited by 72 publications

(88 citation statements)

References 27 publications

(32 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…14 remains robust, and it may occur to some other SMMs where the ground-state spin is large and the ground-state spin multiplet is reasonably well separated in energy from the low-lying excited spin multiplets. Some experimental studies 4,5,10,11 show that upon deposition of Mn 12 molecules on an Au surface, the valence states of all of the Mn ions are preserved while some other experimental works 8,9,12 reveal that such a deposition induces changes in the valence states of some of the Mn ions. In cases where such changes do not occur, 4,5,10,11 the spin-filtering effect is expected.…”

Section: Discussionmentioning

confidence: 99%

“…Recently, molecular junctions based on single-molecule magnets ͑SMMs͒ connected to electrodes or monolayers of SMMs at surfaces, have been fabricated and their electron-transport characteristics [1][2][3][4][5][6] have been measured, as well as their mechanical, electronic, and magnetic properties. [7][8][9][10][11][12][13] Electron transport through an SMM drew a lot of attention because of the intriguing interplay between its transport properties and the internal magnetic degrees of freedom, which is absent in transport through small organic molecules. An SMM consists of several transition metal ions interacting through organic or inorganic ligands via superexchange interactions.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of bonding type and interface geometry on coherent transport through the single-molecule magnetMn12

et al. 2010

View full text Add to dashboard Cite

We examine theoretically coherent electron transport through the single-molecule magnet Mn 12 , bridged between Au͑111͒ electrodes, using the nonequilibrium Green's function method and the density-functional theory. We analyze the effects of bonding type, molecular orientation, and geometry relaxation on the electronic properties and charge and spin transport across the single-molecule junction. We consider nine interface geometries leading to five bonding mechanisms and two molecular orientations: ͑i͒ Au-C bonding, ͑ii͒ Au-Au bonding, ͑iii͒ Au-S bonding, ͑iv͒ Au-H bonding, and ͑v͒ physisorption via van der Waals forces. The two molecular orientations of Mn 12 correspond to the magnetic easy axis of the molecule aligned perpendicular ͓hereafter denoted as orientation ͑1͔͒ or parallel ͓orientation ͑2͔͒ to the direction of electron transport. We find that the electron transport is carried by the lowest unoccupied molecular orbital ͑LUMO͒ level in all the cases that we have simulated. Relaxation of the junction geometries mainly shifts the relevant occupied molecular levels toward the Fermi energy as well as slightly reduces the broadening of the LUMO level. As a result, the current slightly decreases at low bias voltage. Our calculations also show that placing the molecule in the orientation ͑1͒ broadens the LUMO level much more than in the orientation ͑2͒ due to the internal structure of the Mn 12 . Consequently, junctions with the former orientation yield a higher current than those with the latter. Among all of the bonding types considered, the Au-C bonding gives rise to the highest current ͑about one order of magnitude higher than the Au-S bonding͒, for a given distance between the electrodes. The current through the junction with other bonding types decreases in the order of Au-Au, Au-S, and Au-H. Importantly, the spin-filtering effect in all the nine geometries stays robust and their ratios of the majority-spin to the minorityspin transmission coefficients are in the range of 10 3 -10 8 . The general trend in transport among the different bonding types and molecular orientations obtained from this study may be applicable to other single-molecule magnets.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effects of bonding type and interface geometry on coherent transport through the single-molecule magnetMn12

et al. 2010

View full text Add to dashboard Cite

show abstract

“…However, any practical application of SMM requires their interaction with the macroscopic world, to allow read-and-write processes. A possible approach to this end is deposition of SMM on conductive surfaces, which, however, often leads to SMM decomposition 13,14 . Carbon nanotubes (NT) offer an excellent solution to connecting SMM to the outside world, without attendant problems of deterioration of the SMM functionality.…”

mentioning

confidence: 99%

Encapsulation of single-molecule magnets in carbon nanotubes

et al. 2011

View full text Add to dashboard Cite

next-generation electronic, photonic or spintronic devices will be based on nanoscale functional units, such as quantum dots, isolated spin centres or single-molecule magnets. The key challenge is the coupling of the nanoscale units to the macroscopic world, which is essential for read and write purposes. Carbon nanotubes with one macroscopic and two nanoscopic dimensions provide an excellent means to achieve this coupling. Although the dimensions of nanotube internal cavities are suitable for hosting a wide range of different molecules, to our knowledge, no examples of molecular magnets inserted in nanotubes have been reported to date. Here we report the successful encapsulation of single-molecule magnets in carbon nanotubes, yielding a new type of hybrid nanostructure that combines all the key single-molecule magnet properties of the guest molecules with the functional properties of the host nanotube. The findings may pave the way to the construction of spintronic or ultrahigh-density magnetic data storage devices.

show abstract

“…The ∼1 eV HOMO-LUMO gap at U = 4 eV for ligand -CH 3 in low-spin state matches the experimental value. 40,42 As for the low spin states, GGA+U calculations do not show much difference in the electronic properties discussed in previous sections, since both GGA and GGA+U calculations give a large gap for the spin-down channels. The same conclusion, that DFT+U calculations show results similar to GGA calculations for Mn 12 low spin states, has also been made for Mn 12 adsorption on a Ni(111) surface.…”

Section: Magnetic Anisotropy Barriermentioning

confidence: 97%

“…[13][14][15][16][17][18][19] To understand the effect of physical environment on properties of SMMs, especially that of a supporting substrate, it is desirable to place Mn 12 on well-defined surfaces and investigate the electronic and magnetic properties of individual molecules and monolayers. Much effort has already been made to deposit Mn 12 on various substrates, such as the metal Au(111), 20,21 the semi-metal Bi(111), 22 and even the ferromagnetic substrate Ni(111). 23 However, to our knowledge, first-principles methods have not been used to study hybrid nanoarchitectures consisting of SMMs (Mn 12 ) and graphitic materials.…”

Section: Introductionmentioning

confidence: 99%

Single-molecule magnetMn12on graphene

Fry

Cheng

2014

Phys. Rev. B

View full text Add to dashboard Cite

We study energetics, electronic and magnetic structures, and magnetic anisotropy barriers of a monolayer of single-molecule magnets (SMM), [Mn 12 O 12 (COOR) 16 ](H 2 O) 4 (abbreviated as Mn 12 , with R=H, CH 3 , C 6 H 5 and CHCl 2 ), on a graphene surface using spin-polarized density-functional theory with generalized gradient corrections and the inclusion of van der Waals interactions. We find that Mn 12 molecules with ligands -H, -CH 3 , and -C 6 H 5 are physically adsorbed on graphene through weak van der Waals interactions, and a much stronger ionic interaction occurs using a -CHCl 2 ligand. The strength of bonding is closely related to the charge transfer between the molecule and the graphene sheet and can be manipulated by strain in the graphene; specifically, tension enhances n-doping of graphene and compression encourages p-doping. The magnetic anisotropy barrier is computed by including the spin-orbit interaction within density-functional theory. The barriers for the Mn 12 molecules with ligands -H, -CH 3 and -C 6 H 5 on graphene surfaces remain unchanged (within 1 K) from those of isolated molecules because of their weak interaction, and a much larger reduction (10 K) is observed when using the -CHCl 2 ligand on graphene due to a substantial structural deformation as a consequence of the much stronger interaction. Neither strain in graphene nor charge transfer affects the magnetic anisotropy barrier significantly. Finally, we discuss the effect of strong correlation in the high spin state of a Mn 12 SMM and the consequence in SMM-surface adsorption.

show abstract

Electronic structure ofMn12derivatives on the clean and functionalized Au surface

Cited by 72 publications

References 27 publications

Effects of bonding type and interface geometry on coherent transport through the single-molecule magnetMn12

Effects of bonding type and interface geometry on coherent transport through the single-molecule magnetMn12

Encapsulation of single-molecule magnets in carbon nanotubes

Single-molecule magnetMn12on graphene

Contact Info

Product

Resources

About