Atomic force microscopy identification of Al-sites on ultrathin aluminum oxide film
Atomic force microscopy identification of Al-sites on ultrathin aluminum oxide film
复制标题
超薄氧化铝薄膜上铝位点的原子力显微镜鉴定
DOI：
10.1088/0957-4484/26/50/505704
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Y Sugawara and I Štich
中科院分区：
文献类型：
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作者：
Yan Jun Li;J Brndiar;Y Naitoh;Y Sugawara and I Štich
采用非接触式原子力显微镜（AFM）研究了NiAl（110）氧化形成的超薄氧化铝膜在室温超高真空中的微观结构，以期对这一复杂界面的结构和键合有更深入的了解。使用一个非常刚性的硅悬臂梁显着提高分辨率，我们已经获得了前所未有的分辨率，超过了所有以前的结果，这个系统的图像。特别是，我们能够明确地分辨出所有不同配位的铝原子。这是很重要的，因为以前的图像提供了非常不同的图像模式，这不容易与现有的结构模型相协调。实验支持广泛的密度泛函理论建模。我们发现，该系统是强离子和原子力显微镜图像可以可靠地理解从静电势，它提供了一个非常符合实验的图像模型。然而，为了解决更精细的对比度功能，我们提出了一个更复杂的模型的基础上更现实的近似不可分割的氧化铝界面。
Ultrathin alumina film formed by oxidation of NiAl (110) was studied by non-contact atomic force microscopy in an ultra high vacuum at room temperature with the quest to provide the ultimate understanding of structure and bonding of this complicated interface. Using a very stiff Si cantilever with significantly improved resolution, we have obtained images of this system with unprecedented resolution, surpassing all the previous results. In particular, we were able to unambiguously resolve all the differently coordinated aluminum atoms. This is of importance as the previous images provide very different image patterns, which cannot easily be reconciled with the existing structural models. Experiments are supported by extensive density functional theory modeling. We find that the system is strongly ionic and the atomic force microscopy images can reliably be understood from the electrostatic potential which provides an image model in excellent agreement with the experiments. However, in order to resolve the finer contrast features we have proposed a more sophisticated model based on more realistic approximants to the incommensurable alumina interface.