The oxidation corrosion of metallic plutonium, intentional or unavoidable, is a crucial issue for its actual applications. However, the atomistic mechanisms behind such oxidation remain elusive. Through a systematic first principles study of the oxygen diffusion in plutonium dioxide, sesquioxide, and their interface, we obtained some dynamic parameters of oxygen diffusion in different oxides. Moreover, we also discovered a dynamic equilibrium and an anisotropic pathway that prefers the [001] crystallographic direction for oxygen diffusion at their interface. These conclusions were in accord with the experimental results of ceria oxides, an ideal analogue of the plutonium oxides with 4f electrons. These results help us to better understand the mechanisms of oxidation corrosion of plutonium at an atomistic level, and to reveal prospects for applications of the anisotropic orientation-relevant fluorite-structured oxides.

金属钚的有意或不可避免的氧化腐蚀是其实际应用的关键问题。然而，这种氧化背后的原子机制仍然难以捉摸。通过对二氧化钚、三氧化二钚及其界面中氧扩散的系统性第一性原理研究，我们获得了氧在不同氧化物中扩散的一些动态参数。此外，我们还发现了动态平衡和各向异性途径，它们更喜欢 [001] 结晶方向，以便在其界面处进行氧扩散。这些结论与二氧化铈的实验结果一致，二氧化铈是具有 4f 电子的钚氧化物的理想类似物。这些结果有助于我们在原子水平上更好地理解钚的氧化腐蚀机制，