Fracturing a nanoparticle

Abstract

Conventional wisdom and indirect studies suggest that the mechanical properties of nanoparticles can be considerably different than their bulk properties would predict. However, little is actually known about their mechanical behaviour because of the practical difficulties in investigating individual particles. Direct experimental studies of these properties require knowledge of the crystallographic orientation, size and microstructure of the nanoparticle in order to be complete. By deforming a single nanoparticle in the transmission electron microscope we have been able to determine each of these parameters of an isolated silicon nanoparticle a priori. With this approach, we could then directly examine dynamic deformation processes and demonstrate the first direct observation of plasticity-induced cleavage fracture of a silicon nanoparticle in compression.

Acknowledgments

This research was funded through NSF grant number CMS-0322436. This work was also supported in part by the Director, Office of Science, Office of Basic Energy Sciences, of the US Department of Energy under Contract No. DE-AC03-76SF0098. The authors acknowledge support of the staff and facilities at the National Center for Electron Microscopy. We would also like to thank Prof. Steven Girshick and the HPPD research group for providing the particles.