Bin Chen published a paper in PNAS

On February 17, 2014, a paper entitled “Detecting grain rotation at the nanoscale” written by Dr. Bin Chen and co-workers, was published online in Proceedings of the National Academy of Sciences of the United States of America (PNAS), later appearing on the printed issue of March 4, 2014. Dr. Bin Chen is the staff scientist and director of Shanghailaboratory of HPSTAR.

It is well believed that below a certain particle size, grain boundary mediated plastic deformation (e.g., grain rotation, grain boundary sliding and diffusion) substitutes for conventional dislocation nucleation and motion as the dominant deformation mechanism. However, in situ probing of grain boundary processes of ultrafine nanocrystals during plastic deformation has not been feasible, precluding the direct exploration of the nanomechanics. Here in this paper, Dr. Bin Chen and co-workers present the in-situ texturing observation of bulk-sized platinum in nickel pressure media of various particle sizes from 500 nm down to 3 nm. They surprisingly found that the texture strength of the same-sized platinum drops rapidly with decreasing grain size of the nickel medium, indicating that more active grain rotation occurs in the smaller nickel nanocrystals. Insight into these processes provides a better understanding of the plastic deformation of nanomaterials in a few-nanometer length scale.