Quantitative modelling in scanning force microscopy on insulators
Quantitative modelling in scanning force microscopy on insulators
复制标题
绝缘体扫描力显微镜的定量建模
DOI：
10.1016/s0169-4332(01)00943-6
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发表时间：
2002
影响因子：
6.7
通讯作者：
R. Nieminen
中科院分区：
文献类型：
--
作者：
A. Foster;A. Shluger;R. Nieminen
我们分析了绝缘体上非接触原子力显微镜(NC-AFM)的对比度形成机制，并通过理论模型与实验的比较来确定针尖和表面的性质。对CaF2(111)表面的计算结果提供了针尖-表面相互作用的特征、针尖的锐度和静电势以及成像的距离范围的信息。我们分析了成像距离上的静电势知识是否足以解释图像，并表明考虑表面变形对于定量理解图像对比度至关重要。然后我们转向一个更复杂的CaCO3(1014)表面，它有一个复杂的阴离子。我们证明了在离子针尖的情况下，CO_2-−基团的原子结构是无法分辨的，并且我们还研究了成像对针尖取向的依赖关系。同样，针尖在扫描过程中引起的表面变形对图像对比度起着至关重要的作用。我们认为，如果某些体系的针尖结构、势能和观测图像之间的关系能够唯一地建立起来，那么这些体系可以为进一步研究针尖的特性提供参考。
We analyse the mechanisms of contrast formation in non-contact atomic force microscopy (NC-AFM) on insulators and use comparisons of theoretical models with experiment to establish tip and surface properties. The results for the CaF2(111) surface provide information about the character of the tip–surface interaction, tip sharpness and electrostatic potential, and the distance range of imaging. We analyse whether knowledge of the electrostatic potential at the imaging distance is enough to interpret the image and show that account of the surface deformation is crucial for quantitative understanding of the image contrast. Then we turn to a more complex CaCO3(1014) surface, which has a complex anion. We demonstrate that with an ionic tip the atomic structure of the CO32−group cannot be resolved, and we also study the dependence of imaging on the tip orientation. Again, the surface deformation induced by the tip during scanning plays a crucial role in image contrast. We argue that if the relation between the tip structures, potential and observed image could be uniquely established for some systems, these systems could serve as a reference for tip characterisation in further studies.