ABSTRACT An α-Al2O3 bicrystal with a (104)/[110] Σ13 grain boundary was fabricated by joining two pieces of single crystal at 1500°C in an Ar–H2 mixture gas. The resultant grain boundary was characterised by scanning transmission electron microscopy (STEM) at the atomic level. STEM observations revealed that the grain boundary consists of two regions with different atomic structures. These two structures were identified to be the most and second-most stable structures by theoretical calculations and STEM image simulation. The coexistence of two different structures in the Σ13 grain boundary is discussed.

中文翻译：

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α-Al2O3中Σ13金字塔孪晶界中两种不同原子结构的共存

摘要 具有 (104)/[110] Σ13 晶界的 α-Al2O3 双晶是通过在 1500°C 下在 Ar-H2 混合气体中连接两片单晶制备的。通过原子水平的扫描透射电子显微镜（STEM）表征所得晶界。STEM 观察表明，晶界由两个具有不同原子结构的区域组成。通过理论计算和 STEM 图像模拟，这两种结构被确定为最稳定和第二稳定的结构。讨论了 Σ13 晶界中两种不同结构的共存。