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Structure Models for γ‐Aluminum Oxynitride from Ab Initio Calculations
Author(s) -
Fang Chang Ming,
Metselaar Rudi,
Hintzen Hubertus T.,
With Gijsbertus
Publication year - 2001
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2001.tb01064.x
Subject(s) - pseudopotential , spinel , ab initio , octahedron , density functional theory , materials science , ab initio quantum chemistry methods , aluminium , crystallography , diffraction , ion , thermodynamics , chemistry , computational chemistry , condensed matter physics , crystal structure , physics , molecule , quantum mechanics , metallurgy , organic chemistry
First‐principles calculations based on density‐functional theory (DFT) in the pseudopotential (PP) method have been performed for aluminum oxynitride with the spinel‐type structure (γ‐alon). The calculations show that the face‐centered sublattice of the anions is distorted, even for the hypothetical “ideal”γ‐alon spinel Al 3 O 3 N. Among the different proposed structure models, the model with vacancies on the Al sites (the so‐called “constant anion model”) is preferred, whereas a model with interstitial anions (the so‐called “constant cation model”) is unlikely. These results are in good agreement with the experimental results. The aluminum vacancies reside at the octahedral sites. The calculations also show that, in the structure of the γ‐alons, the O/N atoms are partially ordered. The space group Fd [Threemacr] m , which has been widely accepted for all γ‐alons, represents only the statistically averaged results that are obtained with diffraction techniques.