Reveal the Plastic Deformation Mechanisms of Si Nanowires at the Atomic Scale

[摘要] To safely and reliably use NWs for different kinds of nano devices, the structural evolution of these nanowires under external stress become very important. Here, by using the home-made in situ atomic-scale experimental device, Si nanowire bending experiments were conducted with highresolution transmission electron microscopy. The direct dynamic atomicscale observations revealed that dislocation nucleation, motion, escape and interaction were responsible for the large plastic deformation ability of Si nanowires. The prevalent full dislocation movement and interactions induced the formation of Lomer lock dislocations in the Si nanowires. We directly demonstrated that the continuous straining on the Lomer dislocations induced local atoms disordering in the Si nanowires. These results help to explain the ultra-large plastic deformation ability of Si on the nanometer scale.

[关键词] Si Nanowires;Atomic-scale;in situ;Plastic deformation;High-resolution transmission electron microscopy