Progress in Ultra-High Energy Resolution EELS

Vibrational spectroscopy in the electron microscope The Nion Iris spectrometer [2], incorporated into the Nion High Energy Resolution Monochromated EELS-STEM (HERMES ) system [3] has led to an EELS era in which 5 meV energy resolution can be attained at 30 keV primary energy, and combined with atom-sized electron probes. The progress in energy resolution is illustrated in Fig. Reduced tails of the zero loss peak and better energy resolution make the information content of the more recent spectrum resemble the FTIR spectrum more than the older EELS spectrum, especially in the spectrum region between 50 and 220 meV.