Structure models for γ-aluminum oxynitride from ab initio calculations
Structure models for γ-aluminum oxynitride from ab initio calculations
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DOI：
10.1111/j.1151-2916.2001.tb01064.x
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发表时间：
2001-11-01
影响因子：
3.9
通讯作者：
de With, G
中科院分区：
文献类型：
--
作者：
Fang, CM;Metselaar, R;de With, G
对具有尖晶石型结构（γ-alon）的氧氮化铝进行了赝势（PP）方法中基于密度泛函理论（DFT）的第一性原理计算。计算表明，即使对于假设的“理想”γ-alon 尖晶石 Al3O3N，阴离子的面心亚晶格也是扭曲的。在提出的不同结构模型中，在Al位点上具有空位的模型（所谓的“恒定阴离子模型”）是优选的，而具有间隙阴离子的模型（所谓的“恒定阳离子模型”）不太可能。这些结果与实验结果非常吻合。铝空位位于八面体位点。计算还表明，在γ-alons的结构中，O/N原子是部分有序的。 barm 上的空间群 Fd (3) 已被所有伽玛龙广泛接受，仅代表通过衍射技术获得的统计平均结果。
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 (gamma -alon). The calculations show that the face-centered sublattice of the anions is distorted, even for the hypothetical "ideal" gamma -alon spinel Al3O3N. 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 gamma -alons, the O/N atoms are partially ordered. The space group Fd (3) over barm, which has been widely accepted for all gamma -alons, represents only the statistically averaged results that are obtained with diffraction techniques.