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Title: Defect kinetics in spinels: Long-time simulations of MgAl{sub 2}O{sub 4}, MgGa{sub 2}O{sub 4}, and MgIn{sub 2}O{sub 4}

Abstract

Building upon work in which we examined defect production and stability in spinels, we now turn to defect kinetics. Using temperature accelerated dynamics (TAD), we characterize the kinetics of defects in three spinel oxides: magnesium aluminate MgAl{sub 2}O{sub 4}, magnesium gallate MgGa{sub 2}O{sub 4}, and magnesium indate MgIn{sub 2}O{sub 4}. These materials have varying tendencies to disorder on the cation sublattices. In order to understand chemical composition effects, we first examine defect kinetics in perfectly ordered, or normal, spinels, focusing on point defects on each sublattice. We then examine the role that cation disorder has on defect mobility. Using TAD, we find that disorder creates local environments which strongly trap point defects, effectively reducing their mobility. We explore the consequences of this trapping via kinetic Monte Carlo (KMC) simulations on the oxygen vacancy (V{sub O}) in MgGa{sub 2}O{sub 4}, finding that V{sub O} mobility is directly related to the degree of inversion in the system.

Authors:
; ;  [1]; ;  [2]; ;  [3]
  1. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
  2. Department of Mathematical Sciences, Loughborough University, Loughborough, Leicestershire LE11 3TU (United Kingdom)
  3. Department of Materials, Imperial College, Prince Consort Road, London SW7 2BP (United Kingdom)
Publication Date:
OSTI Identifier:
20957761
Resource Type:
Journal Article
Journal Name:
Physical Review. B, Condensed Matter and Materials Physics
Additional Journal Information:
Journal Volume: 75; Journal Issue: 10; Other Information: DOI: 10.1103/PhysRevB.75.104116; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1098-0121
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALUMINATES; CATIONS; CHEMICAL COMPOSITION; CRYSTAL LATTICES; DEFECTS; KINETICS; MAGNESIUM; MAGNESIUM COMPOUNDS; MONTE CARLO METHOD; OXIDES; OXYGEN; SIMULATION; SPINELS; VACANCIES

Citation Formats

Uberuaga, B P, Voter, A F, Sickafus, K E, Bacorisen, D, Smith, Roger, Ball, J A, and Grimes, R W. Defect kinetics in spinels: Long-time simulations of MgAl{sub 2}O{sub 4}, MgGa{sub 2}O{sub 4}, and MgIn{sub 2}O{sub 4}. United States: N. p., 2007. Web. doi:10.1103/PHYSREVB.75.104116.
Uberuaga, B P, Voter, A F, Sickafus, K E, Bacorisen, D, Smith, Roger, Ball, J A, & Grimes, R W. Defect kinetics in spinels: Long-time simulations of MgAl{sub 2}O{sub 4}, MgGa{sub 2}O{sub 4}, and MgIn{sub 2}O{sub 4}. United States. doi:10.1103/PHYSREVB.75.104116.
Uberuaga, B P, Voter, A F, Sickafus, K E, Bacorisen, D, Smith, Roger, Ball, J A, and Grimes, R W. Thu . "Defect kinetics in spinels: Long-time simulations of MgAl{sub 2}O{sub 4}, MgGa{sub 2}O{sub 4}, and MgIn{sub 2}O{sub 4}". United States. doi:10.1103/PHYSREVB.75.104116.
@article{osti_20957761,
title = {Defect kinetics in spinels: Long-time simulations of MgAl{sub 2}O{sub 4}, MgGa{sub 2}O{sub 4}, and MgIn{sub 2}O{sub 4}},
author = {Uberuaga, B P and Voter, A F and Sickafus, K E and Bacorisen, D and Smith, Roger and Ball, J A and Grimes, R W},
abstractNote = {Building upon work in which we examined defect production and stability in spinels, we now turn to defect kinetics. Using temperature accelerated dynamics (TAD), we characterize the kinetics of defects in three spinel oxides: magnesium aluminate MgAl{sub 2}O{sub 4}, magnesium gallate MgGa{sub 2}O{sub 4}, and magnesium indate MgIn{sub 2}O{sub 4}. These materials have varying tendencies to disorder on the cation sublattices. In order to understand chemical composition effects, we first examine defect kinetics in perfectly ordered, or normal, spinels, focusing on point defects on each sublattice. We then examine the role that cation disorder has on defect mobility. Using TAD, we find that disorder creates local environments which strongly trap point defects, effectively reducing their mobility. We explore the consequences of this trapping via kinetic Monte Carlo (KMC) simulations on the oxygen vacancy (V{sub O}) in MgGa{sub 2}O{sub 4}, finding that V{sub O} mobility is directly related to the degree of inversion in the system.},
doi = {10.1103/PHYSREVB.75.104116},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
issn = {1098-0121},
number = 10,
volume = 75,
place = {United States},
year = {2007},
month = {3}
}