The Role Of Carbon Contamination In Suspended Gold Nanowires

Metallic nanowires represent very interesting systems due to new phenomena such as quantum conductance and unexpected long interatomic distances attaining 0.3-0.5 nm. These large distances represent a challenge for physical interpretation. In this work we present experimental data from transmission electron microscopy and results from ab initio density functional calculations for suspended gold chains. We show that large distances as 0.5 nm can be easily explained by the presence of carbon atoms as contaminants, while distances ranging from 0.29 up to 0.36 nm might be explained as resulting of a mixture of clean stressed and contaminated linear chains. © 2003 Materials Research Society.761138143Landman, U., Luedtke, W.D., Burnham, N.A., Colton, R.J., (1990) Science, 248, p. 454Ohnishi, H., Kondo, Y., Takayanagi, K., (1998) Nature (London), 395, p. 780Rodrigues, V., Ugarte, D., (2001) Phys. Rev. B, 63, p. 073405Kizuka, T., Umehaa, S., Fujisawa, S., (2001) Jpn. J. Appl. Phys, 240, pp. L71Agraït, N., Rodrigo, J.G., Vieira, S., (1993) Phys. Rev. B, 47, p. 12345Pascual, J.I., Mendez, J., Gomez-Herrero, J., Baro, A.M., García, N., Thien Binh, V., (1993) Phys. Rev. Lett, 71, p. 1852Kizuka, T., (1998) Phys. Rev. Lett, 81, p. 4448Kondo, Y., Takayanagi, K., (1997) Phys. Rev. Lett, 79, p. 3455Rodrigues, V., Fuhrer, T., Ugarte, D., (2000) Phys. Rev. Lett, 85, p. 4124Koizumi, H., Oshima, Y., Kondo, Y., Takayanagi, K., (2001) Ultramicroscopy, 88, p. 17C.J. Muller, J.M. van Ruitenbeek, and L.J. de Jongh, Physica (Amsterdam) 191C, 485 (1992)Takai, Y., Kawasaki, T., Kimura, Y., Ikuta, T., Shimizu, R., (2001) Phys. Rev. Lett, 87, p. 106105Kondo, Y., Takayanagi, K., (1999) Bull. Am. Phys. Soc, 44, p. 312Rodrigues, V., Bettini, J., Rocha, A.R., Rego, L.G.C., Ugarte, D., (2002) Phys. Rev. B, 65, p. 153402Rego, L.G.C., Rocha, A.R., Rodrigues, V., Ugarte, D., in pressRodrigues, V., Ugarte, D., (2002) Phys. Stat. Sol. B, 230, p. 475Häkkinen, H., Barnett, R.N., Landman, U., (1999) J. Phys. Chem. B, 103, p. 8814Sørensen, M.R., Brandbyge, M., Jacobsen, K.W., (1998) Phys. Rev. B, 57, p. 3283Legoas, S.B., Galvão, D.S., Rodrigues, V., Ugarte, D., (2002) Phys. Rev. Lett, 88, p. 076105Delley, B., (1990) J. Chem. Phys, 92, p. 508113, 7756 (2000)TITAN is a program suite from Wavefunction, Inc. http://www.wavefun. comLACVP** represents a basis set (developed at Los Alamos National Laboratory) with effective core potentials ECPWang, Y., Perdew, J.P., (1991) Phys. Rev. B, 43, p. 8911Vosko, S.J., Wilk, L., Nusair, M., (1980) Can. J. Phys, 58, p. 120