Abstract：
Herein, we present an atomic in-situ 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.
摘要：
在这里，我们在透射电子显微镜（TEM）中对高能电子束（E-Beam）激发的不同取向的Cu氧化进行了原子原位研究。通过实时跟踪Cu衬底的微观结构演变，高分辨率TEM(HRTEM)图像揭示了取向依赖的氧化机制，其中沿[110]区轴的Cu迁移到表面上并被氧化，而沿[100]区轴的Cu在本体和表面都被完全氧化。不同的氧化机制可归因于氧在Cu结构中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Cu主要迁移到纳米晶体{110}平面上。这种行为将导致氧化物的几何形状更宽,因此促进相邻氧化物的聚集。这些发现对于铜基材料在氧化环境中的实际使用具有重要意义。
