YingCarbon.pdf (35.36 MB)
Modelling defect evolution in irradiated graphite
Version 2 2019-08-05, 14:17
Version 1 2019-08-05, 14:12
journal contribution
posted on 2019-08-05, 14:17 authored by Ying Zhou, Kenny JolleyKenny Jolley, Rhiannon Phillips, Roger Smith, Houzheng WuThe diffusion of point defects after irradiation events in graphite is considered using
high temperature molecular dynamics and adaptive kinetic Monte Carlo. The system is modelled
with a ReaxFF potential model. It is shown that monovacancies can diffuse both within the graphite
layers and also between layers to form stable divacancy and trivacancy structures. Interstitials can
also combine, first forming interlayer strings which transform to ring structures. Separated ring
structures can also combine to form mobile platelets which can be the seed for new layer formation.
When a defective lattice contains a local mixture of vacancies and interstitials, both recombination
and larger defect clusters can form. The Dienes defect, cannot easily occur by direct transformation
as originally proposed, because of high energy barriers but is shown to occur as an intermediate step
in interstitial-defect recombination process. At high temperature the graphite layers bend which has
the effect of enhancing defect motion and changing the relative stability of monovacancy structures.
The consequences of this are discussed.
Funding
EPSRC grant EP/M018822/1, UNIGRAF: Understanding and Improving Graphite for Nuclear Fission
History
School
- Science
Department
- Chemistry
Published in
CarbonVolume
154Pages
192 - 202Publisher
ElsevierVersion
- AM (Accepted Manuscript)
Publisher statement
This paper was accepted for publication in the journal Carbon and the definitive published version is available at https://doi.org/10.1016/j.carbon.2019.07.092Acceptance date
2019-07-27Publication date
2019/08/03Copyright date
2019ISSN
0008-6223Publisher version
Language
- en
Depositor
Prof Roger SmithUsage metrics
Categories
No categories selectedKeywords
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC