Exceptional plasticity of silicon nanobridges

• Published in: Nanotechnology Vol. 22; no. 35; pp. 355704 - 1-6
• Main Authors: Ishida, Tadashi, Cleri, Fabrizio, Kakushima, Kuniyuki, Mita, Makoto, Sato, Takaaki, Miyata, Masaki, Itamura, Noriaki, Endo, Junji, Toshiyoshi, Hiroshi, Sasaki, Naruo, Collard, Dominique, Fujita, Hiroyuki
• Format: Journal Article
• Language: English
• Published: England Institute of Physics 02.09.2011
• Subjects: Covalence; Materials science; Nanocomposites; Nanomaterials; Nanostructure; Plasticity; Silicon; Surface diffusion
• ISSN: 0957-4484; 1361-6528; 1361-6528
• DOI: 10.1088/0957-4484/22/35/355704

The plasticity of covalently bonded materials is a subject at the forefront of materials science, bearing on a wide range of technological and fundamental aspects. However, covalent materials fracture in a brittle manner when the deformation exceeds just a few per cent. It is predicted that a macroscopically brittle material like silicon can show nanoscale plasticity. Here we report the exceptional plasticity observed in silicon nanocontacts ('nanobridges') at room temperature using a special experimental setup combining a transmission electron microscope and a microelectromechanical system. When accounting for surface diffusion, we succeeded in elongating the nanocontact into a wire-like structure, with a fivefold increase in volume, up to more than twenty times the original length. Such a large plasticity was caused by the stress-assisted diffusion and the sliding of the intergranular, amorphous-like material among the nanocrystals.