Adsorption Of Gold Atoms On Carbon Nanotubes

We investigate, using ab initio Density Functional Theory total energy calculations, the interaction of Au atoms with a (6,6) carbon nanotube. We found out that isolated Au atoms are weakly bound to nanotubes, and contrary to Al, Ti and Fe, the most stable site in on top of carbon atoms. The Au-tube binding energy for this site is between -0.3 eV and -0.7 eV, depending on the approximation used for the exchange-correlation functional. The Au adatoms will diffuse very quickly through the C-C bonds, with a barrier along this pathway of ≈0.04 eV. When two Au atoms meet, a strong Au-Au bond is formed, with the resulting dimer being less bound to the nanotube when compared to isolated Au atoms. All these results are similar to what is found for the Al-nanotube interaction. This supports the picture that discrete metallic clusters will be formed on nanotubes when the interaction between them and the metal atom is weak. However, an analysis of Fe adsorption shows that further studies are still needed.3165168Iijima, S., (1991) Nature (London), 354, p. 56Iijima, S., Ichihashi, T., (1993) Nature, 363, p. 603Bethune, D.S., (1993) Nature, 363, p. 605Dresselhaus, M.S., Dresselhaus, G., Avouris, Ph., Carbon nanotubes: Synthesis, structure, properties, and applications (2001) Topics in Applied Physics, p. 80Kong, J., Franklin, N.R., Zhou, C., Chapline, M.G., Peng, S., Cho, K., Dai, H., (2000) Science, 287, p. 622Colllins, P.G., Bradley, K., Ishigami, M., Zettls, A., (2000) Science, 287, p. 1801Zhang, Y., Dai, H., (2000) Appl. Phys. Lett., 77, p. 3015Zhang, Y., Franklin, N.W., Chen, R.R.J., Dai, H., (2000) Chem. Phys. Lett., 331, p. 35Govindaraj, A., Satishkumar, B.C., Nath, M., Rao, C.N., (2000) Chem. Mater., 12, p. 202Yuan, H.J., Xie, P., Xiang, J., Yu, D.P., Xu, J., Xie, S.S., Feng, S.Q., (2001) Solid. State Comm., 119, p. 573Kong, J., Chapline, M.G., Dai, H., (2001) Adv. Mater., 13, p. 1384Peng, S., Cho, K., (2001) Mat. Res. Soc. Symp. Proc., 675, pp. W4.8.1Hohenberg, P., Kohn, W., (1964) Phys. Rev., 136, pp. 864BKohn, W., Sham, L.J., (1965) Phys. Rev., 140, pp. 1133AArtacho, E., Sánchez-Portal, D., Ordejón, P., García, A., Soler, J.M., (1999) Phys. Stat. Sol. (b), 215, p. 809. , and references thereinSankey, O.F., Niklewski, D.J., (1989) Phys. Rev. B, 40, p. 3979Perdew, J.P., Burke, K., Ernzerhof, M., (1996) Phys. Rev. Lett., 77, p. 3865Troullier, N., Martins, J.L., (1991) Phys. Rev. B, 43, p. 1993Zhao, J., Buldum, A., Han, J., Lu, J.P., (2002) Nanotechnol., 13, p. 195S. B. Fagan, R. Mota, A. J. R. da Silva and A. Fazzio, submitted for publicationHeyraud, J.C., Metois, J.J., (1980) Acta Met., 28, p. 2789(1980) J. Cryst. Growth, 50, p. 571Ganz, E., Sattler, K., Clarke, J., (1989) Surf. Sci., 219, p. 3