In:
Solid State Phenomena, Trans Tech Publications, Ltd., Vol. 172-174 ( 2011-6), p. 1022-1027
Abstract:
Kinetic Monte Carlo (KMC) simulation is a valuable tool to investigate configu-ration changes in intermetallic compounds. The elementary process is the jump of an atomfrom a lattice site to a neighboring vacancy. In classical transition state theory the jump ratecontains the energy difference between the original equilibrium state and the saddle point (=transition) state. In traditional KMC the saddle point has mostly received rather careless treat-ment, setting it constant or relating it to the type of jumping atom. In the present work, saddlepoint heights were considered explicitly. Taking L1 2 ordered Ni3Al as an example, jump energyprofiles for various atom environments were calculated ab initio in relaxed configurations ofa 3x3x3 supercell, employing the Nudged Elastic Band method where necessary. From theseresults, effective ’pure’ saddle point heights were extracted. To show the effect on kinetics,simulations of order-order transitions were done with jump probabilities based on these results.When compared to the old assumption of constant saddle point heights, both overall kineticsand detailed jump statistics result considerably changed.
Type of Medium:
Online Resource
ISSN:
1662-9779
DOI:
10.4028/www.scientific.net/SSP.172-174
DOI:
10.4028/www.scientific.net/SSP.172-174.1022
Language:
Unknown
Publisher:
Trans Tech Publications, Ltd.
Publication Date:
2011
detail.hit.zdb_id:
2051138-3
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