skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Threshold displacement energies in rutile TiO2: A molecular dynamics simulation study

Abstract

Threshold displacement energies are determined for Ti and O in rutile TiO2 using molecular dynamics simulations with an empirical model. The simulations involve the introduction of a primary knock-on atom (PKA) with a range of energies (30- 150 eV) in various crystallographic directions at 160 K. We observe the formation of stable Frenkel defects, as well as defect recovery via low-energy interstitial migration mechanisms. The latter causes significant statistical variation between simulation outcomes, which leads to the definition of a defect formation probability. This probability is characterized as a function of PKA energy in order to define the threshold displacement energy and compare with experimental results. Using a probability of 10%, the average threshold displacement energy is around 40 eV for oxygen (comparable to experiment) and 105 eV for titanium. Using a probability of 50%, the values are 65 eV and 130 eV respectively, which may be more appropriate for use in TRIM calculations. In addition, we run a parallel set of calculations using a second empirical model, finding that the detailed results are highly model-dependent, particularly the oxygen defect structures and energies, which are compared to new ab initio data.

Authors:
; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org.:
USDOE
OSTI Identifier:
15020441
Report Number(s):
PNNL-SA-43979
8212a; KC0301020; KC0201020
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Nuclear Instruments and Methods in Physics Research. Section B, Beam Interactions with Materials and Atoms, 239(3):191-201
Country of Publication:
United States
Language:
English
Subject:
rutile; threshold displacement energy; radiation damage; computer simulation; oxide; Environmental Molecular Sciences Laboratory

Citation Formats

Thomas, Bronwyn S., Marks, Nigel A., Corrales, Louis R., and Devanathan, Ram. Threshold displacement energies in rutile TiO2: A molecular dynamics simulation study. United States: N. p., 2005. Web. doi:10.1016/j.nimb.2005.04.065.
Thomas, Bronwyn S., Marks, Nigel A., Corrales, Louis R., & Devanathan, Ram. Threshold displacement energies in rutile TiO2: A molecular dynamics simulation study. United States. doi:10.1016/j.nimb.2005.04.065.
Thomas, Bronwyn S., Marks, Nigel A., Corrales, Louis R., and Devanathan, Ram. Thu . "Threshold displacement energies in rutile TiO2: A molecular dynamics simulation study". United States. doi:10.1016/j.nimb.2005.04.065.
@article{osti_15020441,
title = {Threshold displacement energies in rutile TiO2: A molecular dynamics simulation study},
author = {Thomas, Bronwyn S. and Marks, Nigel A. and Corrales, Louis R. and Devanathan, Ram},
abstractNote = {Threshold displacement energies are determined for Ti and O in rutile TiO2 using molecular dynamics simulations with an empirical model. The simulations involve the introduction of a primary knock-on atom (PKA) with a range of energies (30- 150 eV) in various crystallographic directions at 160 K. We observe the formation of stable Frenkel defects, as well as defect recovery via low-energy interstitial migration mechanisms. The latter causes significant statistical variation between simulation outcomes, which leads to the definition of a defect formation probability. This probability is characterized as a function of PKA energy in order to define the threshold displacement energy and compare with experimental results. Using a probability of 10%, the average threshold displacement energy is around 40 eV for oxygen (comparable to experiment) and 105 eV for titanium. Using a probability of 50%, the values are 65 eV and 130 eV respectively, which may be more appropriate for use in TRIM calculations. In addition, we run a parallel set of calculations using a second empirical model, finding that the detailed results are highly model-dependent, particularly the oxygen defect structures and energies, which are compared to new ab initio data.},
doi = {10.1016/j.nimb.2005.04.065},
journal = {Nuclear Instruments and Methods in Physics Research. Section B, Beam Interactions with Materials and Atoms, 239(3):191-201},
number = ,
volume = ,
place = {United States},
year = {Thu Sep 01 00:00:00 EDT 2005},
month = {Thu Sep 01 00:00:00 EDT 2005}
}