EELS log-ratio technique for specimen-thickness measurement in the TEM

✍ Scribed by Malis, T. ;Cheng, S. C. ;Egerton, R. F.

• Publisher: Wiley (John Wiley & Sons)
• Year: 1988
• Tongue: English
• Weight: 591 KB
• Volume: 8
• Category: Article
• ISSN: 0741-0581
• DOI: 10.1002/jemt.1060080206

✦ Synopsis

We discuss measurement of the local thickness t of a transmission microscope specimen from the log-ratio formula t = h In (It&) where It and I0 are the total and zero-loss areas under the electron-energy loss spectrum. We have measured the total inelastic mean free path h in 11 materials of varying atomic number Z and have parameterized the results in the form h = 106F (E@,)lln (2PE@,) where F = (l+Ed1,022)/(1 +E&W2, the incident energy Eo is in keV, the spectrum collection semiangle is in mrad, and Em = 7.62°.36. This formulation should allow absolute thickness to be determined to an accuracy of +20% in most inorganic specimens.