Prospects for Trace Analysis in the Analytical Electron Microscope

Abstract

The analytical electron microscope (AEM) uses a high energy (>100 kV) beam of electrons to generate a range of signals from a thin foil sample as shown in figure la [1,2]. Various detectors are configured in the AEM to pick up most of the generated signals (fig. lb). Microanalysis is usually performed using the characteristic x-ray signal, detected by an energy dispersive spectrometer (EDS) although occasionally the electron energy loss spectrum is also used. This paper will emphasize x-ray microanalysis only. The specific advantages that the AEM has for microanalysis are two-fold. First the instrument can be operated as a high resolution transmission electron microscope, thus permitting the analytical information to be related directly to the microstructure of the sample. Second, in the AEM most microanalysis is performed with a probe size

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痕量分析在分析电镜中的应用前景

分析电子显微镜(AEM)使用高能(>100千伏)电子束从薄片样品中产生一系列信号，如图la[1,2]所示。在AEM中配置了各种探测器，以拾取大多数生成的信号(图lb)。微量分析通常使用特征x射线信号进行，由能量色散光谱仪(EDS)检测，尽管偶尔也使用电子能量损失谱。本文只强调x射线微量分析。AEM对微量分析的特殊优势是双重的。首先，该仪器可以作为高分辨率透射电子显微镜操作，从而允许分析信息与样品的微观结构直接相关。其次，在AEM中，大多数微量分析是在探针尺寸< z10 nm和样品厚度< = 100 nm的情况下进行的。这导致在批量微量分析中通常遇到的分析体积为10'，例如，在电子探针微量分析仪(EPMA)中。这种小体积意味着微量分析的空间分辨率相对较好(通常<50 nm)，但通常在AEM中进行痕量分析相对困难，因为产生的信号强度较低。

本文章由计算机程序翻译，如有差异，请以英文原文为准。