Fri, 25 Jul 2008 04:32:15 BST CiteULike: dchens Srolovitz http://www.citeulike.org/user/dchen/author/Srolovitz CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dchen/article/2675305 <i>Physical Review B (Condensed Matter and Materials Physics), Vol. 74, No. 11. (2006)</i><br /><br />Molecular dynamics simulations were employed to study atomic motion within stationary and migrating asymmetric tilt grain boundaries. We employ several measures of the "complexity" of the atomic trajectories, including the van Hove correlation function, the non-Gaussian parameter, and dynamic entropy. There are two key types of dynamical events within the grain boundaries (i) a stringlike cooperative motions parallel to the tilt axis and occurring on a characteristic time scale of 25  ps and (ii) atomic motion across the grain boundary plane occurring on a characteristic time scale of 150  ps. The characteristic times associated with each type of event decreases with increasing driving force for boundary migration. We present evidence as to how the driving force biases these types of events, leading to boundary migration. While the stringlike atomic motion is an intrinsic feature of grain boundary dynamics and is important for grain boundary migration, it is the second type of event that controls grain boundary migration rates. Characterization of atomic motion governing grain boundary migration Hao Zhang David Srolovitz Jack Douglas James Warren doi:10.1103/PhysRevB.74.115404 Physical Review B (Condensed Matter and Materials Physics), Vol. 74, No. 11. (2006) 2008-04-15T20:22:51-00:00 2006 Physical Review B (Condensed Matter and Materials Physics) 74 11 APS cluster cooperative grain