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   COLLOQUIUM OF THE LABORATORY FOR COMPUTER DESIGN OF MATERIALS        
                   School of Computational Sciences	
                           (CSI 898-Sec 001) 
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        Atomistic simulation of point defects in grain boundaries

                             A. Suzuki
       School of Computational Sciences, George Mason University

Atomic mechanisms of point-defect generation and annihilation in 
several symmetrical [001], [011] and [111] tilt grain boundaries 
are studied by molecular dynamics with an embedded-atom potential. 
Both processes involve collective displacements of atomic cascades 
and show similar features in different grain boundaries. The easiest 
atomic mechanisms of point-defect migration in the grain boundaries 
are identified by molecular dynamics. The respective transition rates 
are calculated within the harmonic transition state theory combined 
with the nudged elastic band method. Vacancies move by either 
single-atom jumps or "long" jumps involving 2-3 atoms. Interstitials 
always move by collective jumps. The trends in grain boundaries 
energies and point-defect properties (generation, annihilation 
and migration) are analyzed across the set of grain boundaries 
studied in this work.

                        Monday , November 20, 2000
                                  4:30 pm
                        Room 206, Science & Tech. I

Refreshments will be served at 4:15 PM.
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Find the schedule at http://csi.gmu.edu/lcdm/seminar/schedule.html