Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Non-stoichiometry in MgAl2O4 spinel
AU - Murphy, S. T.
AU - Gilbert, C. A.
AU - Smith, R.
AU - Mitchell, T. E.
AU - Grimes, R. W.
PY - 2010
Y1 - 2010
N2 - Stoichiometric magnesium aluminate spinel, MgAl2O4, contains equimolar proportions of Al2O3 and MgO. Spinel can, however, exhibit significant deviations from this stoichiometric composition. There is considerable disagreement concerning which species compensate for either excess Al2O3 or MgO non-stoichiometry. Here, we use empirical and quantum mechanical (density functional theory) atomistic simulation techniques to investigate the defect chemistry accommodating non-stoichiometry. The incorporation of excess Al2O3 was found to be a lower energy process than the solution of excess MgO. Elevated magnesium and aluminium cation vacancy defect concentrations are predicted in Al2O3 rich spinels, whilst MgO excess is facilitated by a combination of oxygen vacancy and magnesium interstitial defects.
AB - Stoichiometric magnesium aluminate spinel, MgAl2O4, contains equimolar proportions of Al2O3 and MgO. Spinel can, however, exhibit significant deviations from this stoichiometric composition. There is considerable disagreement concerning which species compensate for either excess Al2O3 or MgO non-stoichiometry. Here, we use empirical and quantum mechanical (density functional theory) atomistic simulation techniques to investigate the defect chemistry accommodating non-stoichiometry. The incorporation of excess Al2O3 was found to be a lower energy process than the solution of excess MgO. Elevated magnesium and aluminium cation vacancy defect concentrations are predicted in Al2O3 rich spinels, whilst MgO excess is facilitated by a combination of oxygen vacancy and magnesium interstitial defects.
KW - non-stoichiometry
KW - spinel
KW - atomistic simulation
KW - defect structures
KW - MAGNESIUM ALUMINATE SPINEL
KW - CRYSTALS
KW - IRRADIATION
KW - SYSTEM
KW - DAMAGE
KW - ION
U2 - 10.1080/14786430903341402
DO - 10.1080/14786430903341402
M3 - Journal article
VL - 90
SP - 1297
EP - 1305
JO - Philosophical Magazine
JF - Philosophical Magazine
SN - 1478-6435
IS - 10
ER -