Multi-Sun EELS: Ultra-High Energy Resolution combined with High Spatial Resolution and High Beam Current

Abstract

Since its introduction in 2014, vibrational spectroscopy in the electron microscope [1] has led to many remarkable results. Examples include distinguishing between 13 C vs 12 C in an amino acid (L-alanine) and mapping their distribution with ~30nm resolution [2], detecting the vibrational signal from a single defect in a solid [3], and recording the vibrational spectrum of a single atom [4]. Other examples can be found in a recent review of the progress [5]. The field continues to advance rapidly, facilitated by continuing advances in the monochromator and the spectrometer [6], and by the development of new operating modes. Figure 1(a) shows a monochromated zero loss peak (ZLP) acquired at 60 kV with a full width at half maximum (FWHM) of 3.2 meV, using a beam current of 0.3 pA.