Publicado em 30/01/2009
Nano Science News, Janeiro de 2009
Though nanotechnology is an extremely active area of research, nature still keeps many secrets about nanostructures. One of those secrets, however, has just been revealed in an article published in Nature Nanotechnology. Researchers from the State University of Campinas (Unicamp) and the Brazilian Synchrotron Light Laboratory (LNLS), in Brazil, discovered a new and completely unexpected family of metallic nanotubes.
The study, coordinated by Professor Daniel Ugarte and Professor Douglas Galvão, identified how silver nanowires deform and finally break. During that process, it was observed the spontaneous formation of structures that are hollow and have a square basis, which is the smallest possible with just four atoms in the cross-section. “This hollow or tubular atomic arrangement is completely unexpected and is formed when nanowires are subjected to a high rate of stretching”, says Ugarte. During stretching, the atoms change their distribution or structure generating a soft structure capable of absorbing a huge tensile deformation. No previous work had considered the possible existence of such a structure
The discovery was based on data from high resolution transmission electron microscopy (HRTEM). ”Theoretical calculations methods suggest that the stability of these structures could be the result of a fortuitous combination of size and high stress regime“, says Professor Galvão.
The results provide essential information to evaluate the possible use of metal nanopieces as structural reinforcement or electric conductor in electronic nanodevices. “This unexpected discovery also opens new possibilities for the study of metallic nanostructures and suggests that perhaps other exotic structures may exist”, emphasizes Ugarte.
Paper: Observation of the Smallest nanotube with metal square-cross-section
M. J. Lagos, F. Sato, J. Bettini, V. Rodrigues, D.S. Galvão, D. Ugarte
Phone: + 55 19 3521-5384 / 3512-1256
LNLS Communication Department
Phone: + 55 19 3512-1267 / + 55 19 3512-1250