Experimental and theoretical study of the detection limits in electron energy-loss spectroscopy

✍ Scribed by M.K.H Natusch; C.J Humphreys; N Menon; O.L Krivanek

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 257 KB
• Volume: 30
• Category: Article
• ISSN: 0968-4328
• DOI: 10.1016/s0968-4328(99)00021-9

✦ Synopsis

We have developed a theoretical model that successfully predicts the spectral signal-to-noise ratios (SNRs) of inner-shell excitations in electron energy-loss spectroscopy of amorphous specimens by computing artificial spectra taking account of valence electron excitations as determined by the Ritchie-Howie model, inner-shell excitations from Hartree-Slater cross-sections and elastic scattering given by Lenz cross-sections together with the noise characteristics of the detection system. The consideration of multiple scattering in our model allows us to apply it to a wide range of specimen thicknesses and collection angles. We apply this model to the detection of minority elements which requires the correct identification of a weak signal on top of a large background in the presence of noise. The detectability of the minority element is judged by the confidence limits in the SNR of their characteristic excitation.