Abstract Single crystal and textured polycrystalline γ-Al2O3 thin films were synthesized by oxidation of NiAl(110) in air at 850 °C for 1 and 2 h, respectively, and used to evaluate the accuracy of two spinel-based and two nonspinel models by comparison of selected-area electron diffraction (SAED). The lattice interplanar distances derived from the polycrystalline SAED pattern most closely matched the cubic spinel γ-Al2O3 model. The single-crystal SAED spot pattern showed symmetry consistent with both the cubic spinel and tetragonal nonspinel models, however, the Al cation distribution better matched the cubic spinel model based on the relative intensities of diffraction spots. Our work indicates that the traditional cubic spinel model is a more accurate model of γ-Al2O3 than the other models considered. The spinel-based monoclinic model is also more accurate than the monoclinic nonspinel model. The understanding of the relative accuracy of the different models is key for simulating γ-Al2O3 containing systems and is of general interest for the metal oxide and ceramic communities.

中文翻译：

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通过高质量结晶 γ-Al2O3 的选区电子衍射评估常见 γ-Al2O3 结构模型的精度

摘要 通过 NiAl(110) 在空气中在 850 °C 下氧化 1 小时和 2 小时，分别合成了单晶和织构多晶 γ-Al2O3 薄膜，并用于评估两种基于尖晶石和两种非尖晶石模型的精度。选区电子衍射 (SAED) 的比较。源自多晶 SAED 图案的晶格面间距与立方尖晶石 γ-Al2O3 模型最接近。单晶 SAED 斑点图案显示出与立方尖晶石和四方非尖晶石模型一致的对称性，然而，基于衍射斑点的相对强度，Al 阳离子分布更好地匹配立方尖晶石模型。我们的工作表明，传统的立方尖晶石模型是比其他考虑的模型更准确的 γ-Al2O3 模型。基于尖晶石的单斜模型也比单斜非尖晶石模型更准确。了解不同模型的相对精度是模拟含 γ-Al2O3 系统的关键，也是金属氧化物和陶瓷社区的普遍关注点。