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Title: Molecular Dynamics Modeling of the Thermal Conductivity of Irradiated SiC as a Function of Cascade Overlap

Abstract

SiC thermal conductivity is known to decrease under irradiation. To understand this effect, we study the variation of the thermal conductivity of cubic SiC with defect accumulation induced by displacement cascades. We use an empirical potential of the Tersoff type in the framework of non-equilibrium molecular dynamics. The conductivity of SiC is found to decrease with dose, in very good quantitative agreement with low temperature irradiation experiments. The results are analyzed in view of the amorphization states that are created by the cascade accumulation simulations. The calculated conductivity values at lower doses are close to the smallest measured values after high temperature irradiation, indicating that the decrease of the conductivity observed at lower doses is related to the creation of point defects. A subsequent decrease takes place upon further cascade accumulation. It is characteristic of the amorphization of the material and is experimentally observed for low temperature irradiation only.

Authors:
; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org.:
USDOE
OSTI Identifier:
899801
Report Number(s):
PNNL-SA-53258
8208; KC0201020; TRN: US200709%%130
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics, 101(2):023527
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; SILICON CARBIDES; IRRADIATION; POINT DEFECTS; THERMAL CONDUCTIVITY; MOLECULAR DYNAMICS METHOD; Silicon Carbide; Molecular Dynamics; Thermal Conductivity; Radiation Damage; Environmental Molecular Sciences Laboratory

Citation Formats

Crocombette, J.-P., Dumazer, Guillaume, Hoang, Nguyen Q., Gao, Fei, and Weber, William J. Molecular Dynamics Modeling of the Thermal Conductivity of Irradiated SiC as a Function of Cascade Overlap. United States: N. p., 2007. Web. doi:10.1063/1.2431397.
Crocombette, J.-P., Dumazer, Guillaume, Hoang, Nguyen Q., Gao, Fei, & Weber, William J. Molecular Dynamics Modeling of the Thermal Conductivity of Irradiated SiC as a Function of Cascade Overlap. United States. doi:10.1063/1.2431397.
Crocombette, J.-P., Dumazer, Guillaume, Hoang, Nguyen Q., Gao, Fei, and Weber, William J. Mon . "Molecular Dynamics Modeling of the Thermal Conductivity of Irradiated SiC as a Function of Cascade Overlap". United States. doi:10.1063/1.2431397.
@article{osti_899801,
title = {Molecular Dynamics Modeling of the Thermal Conductivity of Irradiated SiC as a Function of Cascade Overlap},
author = {Crocombette, J.-P. and Dumazer, Guillaume and Hoang, Nguyen Q. and Gao, Fei and Weber, William J.},
abstractNote = {SiC thermal conductivity is known to decrease under irradiation. To understand this effect, we study the variation of the thermal conductivity of cubic SiC with defect accumulation induced by displacement cascades. We use an empirical potential of the Tersoff type in the framework of non-equilibrium molecular dynamics. The conductivity of SiC is found to decrease with dose, in very good quantitative agreement with low temperature irradiation experiments. The results are analyzed in view of the amorphization states that are created by the cascade accumulation simulations. The calculated conductivity values at lower doses are close to the smallest measured values after high temperature irradiation, indicating that the decrease of the conductivity observed at lower doses is related to the creation of point defects. A subsequent decrease takes place upon further cascade accumulation. It is characteristic of the amorphization of the material and is experimentally observed for low temperature irradiation only.},
doi = {10.1063/1.2431397},
journal = {Journal of Applied Physics, 101(2):023527},
number = ,
volume = ,
place = {United States},
year = {Mon Jan 15 00:00:00 EST 2007},
month = {Mon Jan 15 00:00:00 EST 2007}
}
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