Fundamental differences in mechanical behavior between two types of crystals at the nanoscale

Phys Rev Lett. 2008 Apr 18;100(15):155502. doi: 10.1103/PhysRevLett.100.155502. Epub 2008 Apr 17.


We present differences in the mechanical behavior of nanoscale gold and molybdenum single crystals. A significant strength increase is observed as the size is reduced to 100 nm. Both nanocrystals exhibit discrete strain bursts during plastic deformation. We postulate that they arise from significant differences in the dislocation behavior. Dislocation starvation is the predominant mechanism of plasticity in nanoscale fcc crystals, while junction formation and hardening characterize bcc plasticity. A statistical analysis of strain bursts is performed as a function of size and compared with stochastic models.

Publication types

  • Research Support, Non-U.S. Gov't