Nanowire gold chains: formation mechanisms and conductance

Journal of Physical Chemistry B

Volumn 104, Issue 39, 2000, Pages 9063-9066

  Häkkinen, Hannu ^a   Barnett, Robert N ^a   Scherbakov, Andrew G ^a   Landman, Uzi ^a  

^a GEORGIA INSTITUTE OF TECHNOLOGY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ATOMS; CHEMICAL BONDS; COMPUTER SIMULATION; ELECTRON TRANSPORT PROPERTIES; GOLD; IONIC CONDUCTION IN SOLIDS; MOLECULAR STRUCTURE; REACTION KINETICS; SPECTROSCOPIC ANALYSIS; WIRE;

DIMERIZED ATOMIC CONFIGURATIONS; DOUBLE STRANDED CONTACT; LINEAR ATOMIC CHAIN; NANOWIRE GOLD CHAINS;

NANOSTRUCTURED MATERIALS;

EID: 0342409547     PISSN: 10895647     EISSN: None     Source Type: Journal    
DOI: 10.1021/jp002691r     Document Type: Article

References (26)

1. Landman, U.; Luedtke, W. D.; Burnham, W. A.; Colton, R. J. Science 1990, 248, 454.
2. Landman, U.; Luedtke, W. D. J. Vac. Sci. Technol. 1991, B9, 414.
3. See, e.g., articles in: Nanowires, Serena, P. A., Garcia, N., Eds.; Kluwer: Dordrecht, 1997.
4. Ohnishi, H.; Kondo, Y.; Takayanagi, K. Nature 1998, 395, 780.
5. 0 conductance plateau, see: Yanson, A. I.; Rubio Bollinger, G.; van der Brom, H. E.; Agraït, N.; van Ruitenbeek, J. M. Nature 1998, 395, 783.
6. Torres, J. A.; Tosatti, E.; Dal Corso, A.; Ercolessi, F.; Kohanoff, J. J.; Di Tolla, F. D.; Soler, J. M. Surf Sci. 1999, 426, L441.
7. Okamoto, M.; Takayanagi, K. Phys. Rev. B 1999, 60, 7808. In this study only s-electrons were included.
8. Sánchez-Portal, D.; Artacho, E.; Junquera, J.; Ordejón, P.; Carcía, A.; Soler, J. M. Phys. Rev. Lett. 1999, 83, 3884.
9. De Maria, L.; Springborg, M. Chem. Phys. Lett. 2000, 323, 293. The statement made in this paper that the studies in refs 7 (D. Sánchez-Portal et al.) and 10 (H. Häkkinen et al.) did not include relativistic effects is erroneous.
10. The calculations were performed using the ab initio Born-Oppenheimer (BO) local-spin-density (LSD) molecular dynamics method (BO-LSD-MD, for details see: Barnett, R. N.; Landman, U. Phys. Rev. B 1993, 48, 2081.
11. 1 valence electrons of a gold atom are described by scalar-relativistic norm-conserving nonlocal pseudopotentials (Troullier, N.; Martins, J. L. Phys. Rev. B 1991, 43, 1993) with a plane-wave basis set (kinetic energy cutoff of 62 Ry).
12. See also: Häkkinen, H.; Barnett, R. N.; Landman, U. Phys. Rev. Lett. 1999, 82, 3264 and ref 10.
13. A preliminary discussion pertaining to the inner-dimerized linear-chain configuration and the adsorption of a methanethiol to it can be found in: Häkkinen, H.; Barnett, R. N.; Landman, U. J. Phys. Chem. B 1999, 103, 8814.
14. In calculations of the conductance we used a recursion-transfer-matrix method (see: Hirose K.; Tsukada, M. Phys. Rev. B 1995, 51, 5278).
15. In this method the transmission of an electron propagating from one electrode to the other through the LDA self-consistent effective potential of the connected nanowire, calculated for each of the relaxed wire configurations and processed according to the procedure described in: Nakamura, A.; Brandbyge, M.; Hansen, L. B.; Jacobsen, K. W. Phys. Rev. Lett. 1999, 82, 1538 , is evaluated using a numerical solution for the stationary states to the Schrodinger equation with scattering boundary conditions.
16. Inside the electrodes, i.e., away from the wire/electrode contact region the effective potential converges to a constant value which is then used to represent the continuation of the electrodes. The solution is achieved via discretization of the Schrodinger equation in slices along the wire axis and using periodic boundary conditions in the transverse directions. Transfer-matrix recursion formalism is used to propagate the solution from one slice to the adjacent one starting from the constant-potential region in one of the electrodes and propagating through the wire into the constant-potential region of the receiving electrode. In these conductance calculations 512 plane waves were used to achieve convergence. Transformation to nonmixing eigen-channels was performed following: Brandbyge, M.; Sørensen, M. R.; Jacobsen, K. W. Phys. Rev. B 1997, 56, 14956.
17. 0.
18. ii = 2.62 Å.
19. ie = 3.07 Å.
20. ie = 2.72 Å.
21. 0) at the final stages of elongation.
22. ie = 2.53 Å.
23. Barnett, R. N.; Landman, U. Nature 1997, 387, 788.
24. Häkkinen, H.; Manninen, M. Europhys. Lett. 1998, 44, 80.
25. In ref 7 it was suggested that experimentally observed linear wires with long interatomic distances would in fact consist of spinning "zigzag" structures having typical Au-Au nearest-neighbor distances, but with only the atoms on the rotation axis visible in HRTEM. However, in such structures even the spinning off-axis atoms should generate enough contrast to be clearly visible for imaging (Ugarte, D., private communication).
26. For instance, while it is well-known that oxygen does not adsorb molecularly on bulk gold, it may interact more strongly with the formed nanobridges of the film, and may even dissociate due to heating/strain effects in the film. Atomic oxygen binds strongly on small gold clusters with typical O-Au distance of 1.9-2.1 Å (Häkkinen, H., unpublished data). Linear chains of alternating Au and O atoms (provided that they would be stable as suspended chains) would thus have Au-Au distances of ≈4 Å. For a discussion of related chemical adsorption effects on the structure and electric transport properties of gold nanowires see ref 10.