Stratton W G, Voyles P M
Department of Material Science and Engineering, University of Wisconsin, Madison, WI 53706-1595, USA.
Ultramicroscopy. 2008 Jul;108(8):727-36. doi: 10.1016/j.ultramic.2007.11.004. Epub 2007 Nov 19.
Fluctuation electron microscopy (FEM) is a quantitative electron microscopy technique in which we use the variance V of spatial fluctuations in nanodiffraction as a function of the diffraction vector magnitude k and real-space resolution R to detect medium-range order in amorphous materials. We have developed a model for V(k, R) from a nanocrystal/amorphous composite, which is an idealized form of the medium-range order in various amorphous materials found by previous FEM measurements. The resulting expression for V(k, R) as a function of the nanocrystal size, nanocrystal volume fraction, and the sample thickness connects the FEM signal to well-defined aspects of the material's structure, emphasizes the need for samples of controlled thickness, and explains in some cases the relative height of peaks in V(k). We give an example of interpreting FEM data in terms of this model using recent experiments on amorphous Al88Y7Fe5.
涨落电子显微镜（FEM）是一种定量电子显微镜技术，在该技术中，我们将纳米衍射中空间涨落的方差V作为衍射矢量大小k和实空间分辨率R的函数，以检测非晶材料中的中程有序。我们从纳米晶体/非晶复合材料开发了一个V(k, R)模型，这是先前FEM测量发现的各种非晶材料中程有序的理想化形式。V(k, R)作为纳米晶体尺寸、纳米晶体体积分数和样品厚度的函数的最终表达式将FEM信号与材料结构的明确方面联系起来，强调了对具有受控厚度的样品的需求，并在某些情况下解释了V(k)中峰值的相对高度。我们使用最近关于非晶Al88Y7Fe5的实验给出了一个根据该模型解释FEM数据的示例。
