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Semi-empirical atomistic study of point defect properties in BCC transition metals

Olsson, Pär LU (2009) In Computational Materials Science 47(1). p.135-145
Abstract
We have constructed a set of embedded atom method (EAM) potentials for Fe, Ta, W and V and used them in order to study point defect properties. The parametrizations of the potentials ensure that the third order elastic constants are continuous and they have been fitted to the cohesive energies, the lattice constants, the unrelaxed vacancy formation energies and the second order elastic constants. Formation energies for different self-interstitials reveals that the $\langle 110 \rangle$ split dumb-bell is the most stable configuration for Fe while for Ta, W and V we find that the $\langle 111 \rangle$ split dumb-bell is preferred. Self-interstitial migration energies are simulated using the nudged elastic band method and the migration... (More)
We have constructed a set of embedded atom method (EAM) potentials for Fe, Ta, W and V and used them in order to study point defect properties. The parametrizations of the potentials ensure that the third order elastic constants are continuous and they have been fitted to the cohesive energies, the lattice constants, the unrelaxed vacancy formation energies and the second order elastic constants. Formation energies for different self-interstitials reveals that the $\langle 110 \rangle$ split dumb-bell is the most stable configuration for Fe while for Ta, W and V we find that the $\langle 111 \rangle$ split dumb-bell is preferred. Self-interstitial migration energies are simulated using the nudged elastic band method and the migration energies for Fe and W are found to be in good agreement with experimental and \emph{ab initio} data. Migration energies for Ta and V self-interstitials are found to be quite low. The calculated formation, activation and migration energies for monovacancies are in good agreement with experimental data. The calculated formation energies for divacancies reveal that the second nearest neighbor divacancy is more energetically favorable than nearest neighbor divacancies and the migration energies indicate that nearest neighbor migration paths are more likely to occur than second nearest neighbor migration jumps. For Fe, we have also studied the influence of the pair potential behavior between the second and third nearest neighbor on the stability of the $\langle 110 \rangle$ split dumb-bell, which revealed that the higher the energy level of the pair potential is in that region, the more stable the $\langle 110 \rangle$ split dumb-bell becomes. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
BCC transition metals, self-interstitials, vacancies, EAM
in
Computational Materials Science
volume
47
issue
1
pages
135 - 145
publisher
Elsevier
external identifiers
  • wos:000272152000018
  • scopus:70350575172
ISSN
0927-0256
DOI
10.1016/j.commatsci.2009.06.025
language
English
LU publication?
yes
id
0ffcbdbb-ded1-4415-9100-96ecfafe3ffe (old id 1496229)
alternative location
http://www.sciencedirect.com.ludwig.lub.lu.se/science?_ob=ArticleURL&_udi=B6TWM-4WXB4YW-1&_user=745831&_coverDate=11%2F30%2F2009&_rdoc=19&_fmt=high&_orig=browse&_srch=doc-info(%23toc%235566%232009%23999529998%231539095%23FLA%23display%23Volume)&_cdi=5566&_sort=d&_docanchor=&_ct=37&_acct=C000041498&_version=1&_urlVersion=0&_userid=745831&md5=b1aa2b239a3b1a614b57bcdbedc7a39b
date added to LUP
2009-10-27 08:32:55
date last changed
2017-09-03 04:24:37
@article{0ffcbdbb-ded1-4415-9100-96ecfafe3ffe,
  abstract     = {We have constructed a set of embedded atom method (EAM) potentials for Fe, Ta, W and V and used them in order to study point defect properties. The parametrizations of the potentials ensure that the third order elastic constants are continuous and they have been fitted to the cohesive energies, the lattice constants, the unrelaxed vacancy formation energies and the second order elastic constants. Formation energies for different self-interstitials reveals that the $\langle 110 \rangle$ split dumb-bell is the most stable configuration for Fe while for Ta, W and V we find that the $\langle 111 \rangle$ split dumb-bell is preferred. Self-interstitial migration energies are simulated using the nudged elastic band method and the migration energies for Fe and W are found to be in good agreement with experimental and \emph{ab initio} data. Migration energies for Ta and V self-interstitials are found to be quite low. The calculated formation, activation and migration energies for monovacancies are in good agreement with experimental data. The calculated formation energies for divacancies reveal that the second nearest neighbor divacancy is more energetically favorable than nearest neighbor divacancies and the migration energies indicate that nearest neighbor migration paths are more likely to occur than second nearest neighbor migration jumps. For Fe, we have also studied the influence of the pair potential behavior between the second and third nearest neighbor on the stability of the $\langle 110 \rangle$ split dumb-bell, which revealed that the higher the energy level of the pair potential is in that region, the more stable the $\langle 110 \rangle$ split dumb-bell becomes.},
  author       = {Olsson, Pär},
  issn         = {0927-0256},
  keyword      = {BCC transition metals,self-interstitials,vacancies,EAM},
  language     = {eng},
  number       = {1},
  pages        = {135--145},
  publisher    = {Elsevier},
  series       = {Computational Materials Science},
  title        = {Semi-empirical atomistic study of point defect properties in BCC transition metals},
  url          = {http://dx.doi.org/10.1016/j.commatsci.2009.06.025},
  volume       = {47},
  year         = {2009},
}