Inelastic mean free path (IMFP) was determined by electron energy loss spectroscopy (EELS) to estimate the accurate thickness of TEM thin foil using needle-shaped specimen. From EELS measurements performed for 99.99% Al, Si wafer and 99.99% Fe, linear relationships were confirmed between the thickness of the TEM thin foil and the ratio of the total intensity of EELS spectrum to the total intensity of zero-loss spectrum for all samples. By weighted least-square fitting, the IMFP was estimated to be 143-150 nm for Al, 159-165 nm for Si with amorphous layer, and 92-94 nm for Fe with the collection semi-angle β = 11.9 - 35.7 mrad, and accelerated voltage of 200 kV. Thus, the dependence of IMFP on β is not dominant. The accuracy depends on the roundness of the cross-section of the needle-shaped specimen, and is observed to be low in terms of percentage in this work.

中文翻译：

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使用针状试样通过 STEM-EELS 技术测量非弹性平均自由程

非弹性平均自由程 (IMFP) 通过电子能量损失光谱 (EELS) 确定，以使用针状试样估计 TEM 薄箔的准确厚度。通过对 99.99% Al、Si 晶片和 99.99% Fe 进行的 EELS 测量，确认了 TEM 薄箔的厚度与所有样品的 EELS 光谱总强度与零损耗光谱总强度之比之间的线性关系. 通过加权最小二乘拟合，估计 IMFP 对于 Al 为 143-150 nm，对于具有非晶层的 Si 为 159-165 nm，对于 Fe 为 92-94 nm，收集半角 β = 11.9 - 35.7 mrad，和200 kV的加速电压。因此，IMFP 对 β 的依赖并不占主导地位。精度取决于针形试样横截面的圆度，