Atomic force microscopy identification of Al-sites on ultrathin aluminum oxide film on NiAl(110). (19th November 2015)

• Record Type: Journal Article
• Authors: Li, Yan Jun; Brndiar, J; Naitoh, Y; Sugawara, Y; Štich, I
• Is Part Of: Nanotechnology. Volume 26:Number 50(2015)
• Publication Date: 2015-11-19
• Subjects: atomic force microscopy -- oxide surfaces -- interface structure -- density functional theory; 68.37.Ps -- 68.35.Ct -- 68.47.Gh -- 68.55.Jk -- 71.15.Mb; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/0957-4484/26/50/505704
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: 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.