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}
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
- Department of Mathematical Sciences, Loughborough University, Loughborough, Leicestershire LE11 3TU (United Kingdom)
- Department of Materials, Imperial College, Prince Consort Road, London SW7 2BP (United Kingdom)
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.
- OSTI ID:
- 20957761
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 75, Issue 10; Other Information: DOI: 10.1103/PhysRevB.75.104116; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- English
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