Two thickness measurement methods using an electron energy loss spectroscopy (EELS) and 10a convergent beam electron diffraction (CBED) were compared in an Fe-18Mn-0.7C alloy. The thin foil specimen was firstly tilted to satisfy 10a two-beam condition. Low loss spectra of EELS and CBED patterns were acquired in scanning transmission electron microscopy (STEM) and TEM-CBED modes under the two-beam condition. The log-ratio method was used for measuring the thin foil thickness. Kossel-Möllenstedt (K-M) fringe of the 13 1 ¯ $$ \mathbf{13}\overline{\mathbf{1}} $$ diffracted disk of austenite was analyzed to evaluate the thickness. The results prove the good coherency between both methods in the thickness range of 72 ~ 113 nm with a difference of less than 5%.

中文翻译：

---

EELS与CBED法试样测厚对比研究

在 Fe-18Mn-0.7C 合金中比较了使用电子能量损失谱 (EELS) 和 10a 会聚束电子衍射 (CBED) 的两种厚度测量方法。薄箔试样首先倾斜以满足 10a 两束条件。在两光束条件下，在扫描透射电子显微镜 (STEM) 和 TEM-CBED 模式中获得了 EELS 和 CBED 图案的低损耗光谱。对数比法用于测量薄箔厚度。分析 13 1 ¯ $$ \mathbf{13}\overline{\mathbf{1}} $$ 奥氏体衍射盘的 Kossel-Möllenstedt (KM) 边缘以评估厚度。结果证明两种方法在72~113 nm厚度范围内具有良好的一致性，差异小于5%。