Herein, we present an atomic investigation of Cu oxidation along different orientations stimulated by high-energy electron beams (E-Beam) in transmission electron microscopy (TEM). By following the microstructural evolution of the Cu substrate in real time, high-resolution TEM (HRTEM) images reveal an orientation-dependent oxidation mechanism, whereby Cu along [110] zone axis migrates onto the surface and be oxidized while Cu along [100] zone axis is oxidized completely both in bulk and at the surface. The different oxidation mechanisms can be attributed to the differing diffusion rates of oxygen in Cu structures along directions. Moreover, the growth of Cu oxides is found to follow a layer-by-layer mechanism, where Cu mostly migrates onto nanocrystal {110} planes. This behavior would lead to the oxides wider in geometric shape and therefore promote the aggregation of adjacent oxides. These findings have important implications for the practical use of copper-based materials in oxidizing environments.

中文翻译：

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原位电子束辐照下 Cu 的取向依赖氧化行为

在此，我们提出了在透射电子显微镜（TEM）中高能电子束（E-Beam）刺激下沿不同方向的铜氧化的原子研究。通过实时跟踪 Cu 基底的微观结构演变，高分辨率 TEM (HRTEM) 图像揭示了一种依赖于方向的氧化机制，其中 Cu 沿 [110] 区轴迁移到表面并被氧化，而 Cu 沿 [100] 区轴迁移到表面并被氧化。区域轴在本体和表面均被完全氧化。不同的氧化机制可归因于铜结构中氧沿方向的不同扩散速率。此外，发现铜氧化物的生长遵循逐层机制，其中铜大部分迁移到纳米晶{110}面上。这种行为会导致氧化物的几何形状变宽，从而促进相邻氧化物的聚集。这些发现对于氧化环境中铜基材料的实际使用具有重要意义。