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Title: Mechanical Properties and Elastic Constants Due to Damage Accumulation and Amorphization in SiC

Abstract

Damage accumulation due to cascade overlap, which was simulated previously, has been used to study the changes of elastic constants, bulk and elastic moduli as a function of dose. These mechanical properties generally decrease with increasing dose, and the rapid decrease at low-dose level indicates that point defects and small clusters play an important role in the changes of elastic constants rather than topological disorder. The internal strain relaxation has no effect on the elastic constants, C11 and C12, in perfect SiC, but it has a significant influence on all elastic constants calculated in damaged SiC. The elastic constants in the cascade-amorphized (CA) SiC decrease about 19%, 29% and 46% for C11, C12 and C44, respectively. The bulk modulus decrease 23% and the elastic modulus decreases 29%, which is consistent with experimental measurements. The stability of both the perfect SiC and CA-SiC under hydrostatic tension has been also investigated. All mechanical properties in the CA-SiC exhibit behavior similar to that in perfect SiC, but the critical stress at which the CA-SiC becomes structurally unstable is one order of magnitude smaller than that for perfect SiC.

Authors:
;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
Sponsoring Org.:
USDOE
OSTI Identifier:
860011
Report Number(s):
PNNL-SA-39837
3448; 8208; KC0201020; TRN: US0504858
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Journal Name:
Physical Review. B, Condensed Matter and Materials Physics
Additional Journal Information:
Journal Volume: 69; Journal Issue: 22
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; SILICON CARBIDES; MECHANICAL PROPERTIES; POINT DEFECTS; ORDER-DISORDER TRANSFORMATIONS; AMORPHOUS STATE; ELASTICITY; RADIATION EFFECTS; environmental molecular sciences laboratory; Mechanical properties; Elastic constants; Damage accumulation; Silicon carbide

Citation Formats

Gao, Fei, and Weber, William J. Mechanical Properties and Elastic Constants Due to Damage Accumulation and Amorphization in SiC. United States: N. p., 2004. Web. doi:10.1103/PhysRevB.69.224108.
Gao, Fei, & Weber, William J. Mechanical Properties and Elastic Constants Due to Damage Accumulation and Amorphization in SiC. United States. https://doi.org/10.1103/PhysRevB.69.224108
Gao, Fei, and Weber, William J. 2004. "Mechanical Properties and Elastic Constants Due to Damage Accumulation and Amorphization in SiC". United States. https://doi.org/10.1103/PhysRevB.69.224108.
@article{osti_860011,
title = {Mechanical Properties and Elastic Constants Due to Damage Accumulation and Amorphization in SiC},
author = {Gao, Fei and Weber, William J},
abstractNote = {Damage accumulation due to cascade overlap, which was simulated previously, has been used to study the changes of elastic constants, bulk and elastic moduli as a function of dose. These mechanical properties generally decrease with increasing dose, and the rapid decrease at low-dose level indicates that point defects and small clusters play an important role in the changes of elastic constants rather than topological disorder. The internal strain relaxation has no effect on the elastic constants, C11 and C12, in perfect SiC, but it has a significant influence on all elastic constants calculated in damaged SiC. The elastic constants in the cascade-amorphized (CA) SiC decrease about 19%, 29% and 46% for C11, C12 and C44, respectively. The bulk modulus decrease 23% and the elastic modulus decreases 29%, which is consistent with experimental measurements. The stability of both the perfect SiC and CA-SiC under hydrostatic tension has been also investigated. All mechanical properties in the CA-SiC exhibit behavior similar to that in perfect SiC, but the critical stress at which the CA-SiC becomes structurally unstable is one order of magnitude smaller than that for perfect SiC.},
doi = {10.1103/PhysRevB.69.224108},
url = {https://www.osti.gov/biblio/860011}, journal = {Physical Review. B, Condensed Matter and Materials Physics},
number = 22,
volume = 69,
place = {United States},
year = {Mon Jun 28 00:00:00 EDT 2004},
month = {Mon Jun 28 00:00:00 EDT 2004}
}