title: Observation of atomic diffusion at twin-modified grain boundaries in copper.
abstract: Grain boundaries affect the migration of atoms and electrons in polycrystalline solids, thus influencing many of the mechanical and electrical properties. By introducing nanometer-scale twin defects into copper grains, we show that we can change the grain-boundary structure and atomic-diffusion behavior along the boundary. Using in situ ultrahigh-vacuum and high-resolution transmission electron microscopy, we observed electromigration-induced atomic diffusion in the twin-modified grain boundaries. The triple point where a twin boundary meets a grain boundary was found to slow down grain-boundary and surface electromigration by one order of magnitude. We propose that this occurs because of the incubation time of nucleation of a new step at the triple points. The long incubation time slows down the overall rate of atomic transport.
authors: Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan, Republic of China.
authors: Kuan-Chia
authors: KC
authors: Chen
authors: Wen-Wei
authors: WW
authors: Wu
authors: Chien-Neng
authors: CN
authors: Liao
authors: Lih-Juann
authors: LJ
authors: Chen
authors: K N
authors: KN
authors: Tu