Modal analysis of dislocation vibration and reaction attempt frequency
Transition state theory is a fundamental approach for temporal coarsegraining. It estimates the reaction rate for a transition processes by quantifying the activation free energy and attempt frequency for the unit process. To calculate the transition rate of a gliding dislocation, the attempt frequency is often obtained from line tension estimates of dislocation vibrations, a highly simplified model of dislocation behavior. This work revisits the calculation of attempt frequency for a dislocation bypassing an obstacle, in this case a selfinterstitial atom (SIA) loop. First, a direct calculation of the vibrational characteristics of a finite pinned dislocation segment is compared to line tension estimates before moving to the more complex case of dislocationobstacle bypass. The entropic factor associated with the attempt frequency is calculated for a finite dislocation segment and for an infinite glide dislocation interacting with an SIA loop. Lastly, it is found to be dislocation length independent for three cases of dislocationself interstitial atom (SIA) loop interactions.
 Authors:

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 Georgia Inst. of Technology, Metz (France)
 Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
 Georgia Inst. of Technology, Atlanta, GA (United States)
 Publication Date:
 Report Number(s):
 LAUR1626394
Journal ID: ISSN 13596454
 Grant/Contract Number:
 AC5206NA25396
 Type:
 Accepted Manuscript
 Journal Name:
 Acta Materialia
 Additional Journal Information:
 Journal Volume: 134; Journal ID: ISSN 13596454
 Publisher:
 Elsevier
 Research Org:
 Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
 Sponsoring Org:
 USDOE Office of Nuclear Energy (NE)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 36 MATERIALS SCIENCE; dislocation; thermal activation; attempt frequency; modal analysis
 OSTI Identifier:
 1343712
Sobie, Cameron, Capolungo, Laurent, McDowell, David L., and Martinez, Enrique. Modal analysis of dislocation vibration and reaction attempt frequency. United States: N. p.,
Web. doi:10.1016/j.actamat.2017.02.005.
Sobie, Cameron, Capolungo, Laurent, McDowell, David L., & Martinez, Enrique. Modal analysis of dislocation vibration and reaction attempt frequency. United States. doi:10.1016/j.actamat.2017.02.005.
Sobie, Cameron, Capolungo, Laurent, McDowell, David L., and Martinez, Enrique. 2017.
"Modal analysis of dislocation vibration and reaction attempt frequency". United States.
doi:10.1016/j.actamat.2017.02.005. https://www.osti.gov/servlets/purl/1343712.
@article{osti_1343712,
title = {Modal analysis of dislocation vibration and reaction attempt frequency},
author = {Sobie, Cameron and Capolungo, Laurent and McDowell, David L. and Martinez, Enrique},
abstractNote = {Transition state theory is a fundamental approach for temporal coarsegraining. It estimates the reaction rate for a transition processes by quantifying the activation free energy and attempt frequency for the unit process. To calculate the transition rate of a gliding dislocation, the attempt frequency is often obtained from line tension estimates of dislocation vibrations, a highly simplified model of dislocation behavior. This work revisits the calculation of attempt frequency for a dislocation bypassing an obstacle, in this case a selfinterstitial atom (SIA) loop. First, a direct calculation of the vibrational characteristics of a finite pinned dislocation segment is compared to line tension estimates before moving to the more complex case of dislocationobstacle bypass. The entropic factor associated with the attempt frequency is calculated for a finite dislocation segment and for an infinite glide dislocation interacting with an SIA loop. Lastly, it is found to be dislocation length independent for three cases of dislocationself interstitial atom (SIA) loop interactions.},
doi = {10.1016/j.actamat.2017.02.005},
journal = {Acta Materialia},
number = ,
volume = 134,
place = {United States},
year = {2017},
month = {2}
}