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Defects, Defect Processes and Ion-Solid Interactions in Ceramics


EMSL Project ID
8208

Abstract

This research will develop a fundamental understanding of the defects, complex dynamic defect processes, and ion-solid interactions in SiC, GaN, ZrSiO4, Gd2TiO7, SrTiO3, and other crystalline ceramics using ab initio pseudopotential and empirical potential molecular dynamics methods. The goal is to determine the energetics of defect formation and migration, the type and number of defects (e.g., vacancies, interstitials, replacements, anti-site defects, defect clusters) produced as a function of incident ion energy and temperature, the effects of overlapped collisions, defect interactions and annealing, and the role of defects in irradiation-induced phase transformations, such as amorphization or decomposition. These results will assist in the interpretation of experimental data and provide input for Monte Carlo simulations and rate theory calculations of how the changes in structure evolve macroscopically at longer time and larger length scales, as a function of temperature.

Project Details

Project type
Capability Research
Start Date
2004-03-24
End Date
2005-12-15
Status
Closed

Team

Principal Investigator

William Weber
Institution
University of Tennessee

Team Members

Zhiguo Wang
Institution
University of Electronic Science and Technology of China

Ram Devanathan
Institution
Pacific Northwest National Laboratory

Fei Gao
Institution
Pacific Northwest National Laboratory

Related Publications

Li Z, S Wang, Z Wang, XT Zu, F Gao, and WJ Weber. 2010. "Mechanical behavior of twinned SiC nanowires under combined tension-torsion and compression-torsion strain." Journal of Applied Physics 108(1):Art. No. 013504. doi:10.1063/1.3456002
Posselt M, F Gao, and H Bracht. 2008. "Correlation between self-diffusion in Si and the migration mechanisms of vacancies and self-interstitials: An atomistic study." Physical Review. B, Condensed Matter 78:035208. doi:10.1103/PhysRevB.78.035208
Rong Z, F Gao, WJ Weber, and Hobler. 2007. "Monte Carlo Simulations of Defect Recovery within a 10 keV Collision Cascade in 3C-SiC." Journal of Applied Physics 102(10):103508, 1-7.
Wang Z, S Wang, J Li, F Gao, and WJ Weber. 2009. "Structure and electronic properties of saturated and unsaturated gallium nitride nanotubes." Journal of Physical Chemistry C 113(44):19281-19285. doi:10.1021/jp907657z.
Wang Z, XT Zu, F Gao, and WJ Weber. 2008. "Nanomechanical Behavior of Single Crystalline SiC Nanotubes Revealed by Molecular Dynamics Simulations." Journal of Applied Physics 104(9):093506. doi:10.1063/1.3005979
Wang Z, XT Zu, Z Li, and F Gao. 2008. "Amorphous layer coating induced brittle to ductile transition in single crystalline SiC nanowires: an atomistic simulation." Journal of Physics D. Applied Physics 41(15):155419. doi:10.1088/0022-3727/41/15/155419
Xiao HY, F Gao, XT Zu, and WJ Weber. 2009. "Threshold displacement energy in GaN; Ab initio molecular dynamics study." Journal of Applied Physics 105(12):123527, 1-5. doi:10.1063/1.3153277
Xiao HY, X Zu, Y Zhang, and F Gao. 2006. "Adsorption of alkali metals on Ge(001)(2?1) surface." Chemical Physics Letters 417(1-3):6-10.
Zhou Y, X Jiang, G Duan, F Gao, and XT Zu. 2010. "Spin and band-gap engineering in copper-doped BN sheet." Chemical Physics Letters 491(4-6):203-207 . doi:10.1016/j.cplett.2010.03.085