Understanding the mechanical properties of nanoscale systems requires a range of measurement techniques and theoretical approaches to gather the relevant physical and chemical information. The arrangements of atoms in nanostructures and macroscopic matter can be different, principally due to the role of surface energy, but the interplay between atomic and electronic structure in association with applied mechanical stress can also lead to surprising differences. For example, metastable structures such as suspended chains of atoms1,2,3 and helical wires4,5 have been produced by stretching metal junctions. Here, we report the spontaneous formation of the smallest possible metal nanotube with a square cross-section during the elongation of silver nanocontacts. Ab initio calculations and molecular simulations indicate that the hollow wire forms because this configuration allows the surface energy to be minimized, and also generates a soft structure capable of absorbing a huge tensile deformation.
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Onishi, H., Kondo, Y. & Takayanagi, K. Quantized conductance through individual rows of suspended gold atoms. Nature 395, 780–783 (1998).
Yanson, A. I., Bollinger, G. R., van den Brom, H. E., Agrait, N. & van Ruitenbeek, J. M. Formation and manipulation of a metallic wire of single gold atoms. Nature 395, 783–785 (1998).
Rodrigues, V. & Ugarte, D. Real-time imaging of atomistic process in one-atom-thick metal junctions. Phys. Rev. B 63, 073405 (2001).
Kondo, Y. & Takayanagi, K. Synthesis and characterization of helical multi-shell gold nanowires. Science 289, 606–608 (2000).
Gülseren, O., Ercolessi, F. & Tosatti, E. Noncrystalline structures of ultrathin unsupported nanowires. Phys. Rev. Lett. 80, 3775–3778 (1998).
Agraït, N., Yeyati, A. L. & van Ruitenbeek, J. M. Quantum properties of atomic-sized conductors. Phys. Rep. 377, 81–279 (2003).
Marks, L. D. Experimental studies of small-particle structures. Rep. Prog. Phys. 57, 603–649 (1994).
Rodrigues, V., Bettini, J., Rocha, A. R., Rego, L. G. C. & Ugarte, D. Quantum conductance in silver nanowires: Correlation between atomic structure and transport properties. Phys. Rev. B 65, 153402 (2002).
Rodrigues, V., Fuhrer, T. & Ugarte, D. Signature of atomic structure in the quantum conductance of gold nanowires. Phys. Rev. Lett. 85, 4124–4127 (2000).
Bettini, J., Rodrigues, V., González, J. C. & Ugarte, D. Real-time atomic resolution study of metal nanowires. Appl. Phys. A 81, 1513–1518 (2005).
González, J. C. et al. Indication of unusual pentagonal structures in atomic-size Cu nanowires. Phys. Rev. Lett. 93, 126103 (2004).
Bettini, J. et al. Experimental realization of suspended atomic chains composed of different atomic species. Nature Nanotech. 1, 182–185 (2006).
Sanchez-Portal, D., Ordejón, P., Artacho, E. & Soler, J. M. Density-functional method for very large systems with LCAO basis sets. Int. J. Quantum Chem. 65, 453–461 (1997).
Soler, J. M. et al. The SIESTA method for ab initio order-N materials simulation. J. Phys.: Condens. Matter 14, 2745–2779 (2002).
Cheng, D., Kim, W. Y., Min, S. K., Nautiyal, T. & Kim, K. S. Magic structures and quantum conductance of  silver nanowires. Phys. Rev. Lett. 96, 096104 (2006).
Jia, J., Shi, D., Zhao, J. & Wang, B. Structural properties of silver nanowires from atomistic descriptions. Phys. Rev. B 76, 165420 (2007).
Rego, L. G. C., Rocha, A. R., Rodrigues, V. & Ugarte, D. Role of structural evolution in the quantum conductance behavior of gold nanowires during stretching. Phys. Rev. B 67, 165420 (2003).
Kondo, Y. & Takayanagi, K. Gold nanobridge stabilized by surface structure. Phys. Rev. Lett. 79, 3455–3458 (1997).
Oshima, Y., Onga, A. & Takayanagi, K. Helical gold nanotube synthesized at 150 K. Phys. Rev. Lett. 91, 205503 (2003).
Lagos, M., Rodrigues, V. & Ugarte, D. Structural and electronic properties of atomic-size wires at low temperatures. J. Electron Spectrosc. Rel. Phenom. 156, 20–24 (2007).
Perdew, J. P. & Zunger, A. Self-interaction correction to density-functional approximations for many-electron systems. Phys. Rev. B 23, 5048–5079 (1981).
Troullier, N. & Martins, J. L. Efficient pseudopotentials for plane-wave calculations. Phys. Rev. B 43, 1993–2006 (1991).
Rodrigues, V., Sato, F., Galvão, D. S. & Ugarte, D. Size limit of defect formation in pyramidal Pt nanocontacts. Phys. Rev. Lett. 99, 255501 (2007).
P.C. Silva is acknowledged for assistance during sample preparation. This work was supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).
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Lagos, M., Sato, F., Bettini, J. et al. Observation of the smallest metal nanotube with a square cross-section. Nature Nanotech 4, 149–152 (2009). https://doi.org/10.1038/nnano.2008.414
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