Applied Microscopy

  • Volume 50
  • /
  • Pages.8.1-8.7
  • /
  • 2020
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  • 2287-5123(pISSN)
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  • 2287-4445(eISSN)
Korean Society of Microscopy (한국현미경학회)
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Comparative study on the specimen thickness measurement using EELS and CBED methods

  • Yoon-Uk Heo (Graduate Institute of Ferrous Technology, Pohang University of Science and Technology)
  • Received : 2020.03.17
  • Accepted : 2020.04.29
  • Published : 2020.12.31
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Abstract

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 $13{\ba{1}}$ 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%.

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