2006/02/15 by John C. H. Spence · 2 citations
Materials Science · Biochemistry, Genetics and Molecular Biology · Physics and Astronomy · #Electron and X-Ray Spectroscopy Techniques #Advanced Electron Microscopy Techniques and Applications #X-ray Spectroscopy and Fluorescence Analysis #Physics #Scanning transmission electron microscopy #Spectroscopy #Electron energy loss spectroscopy #Absorption spectroscopy #Scattering #Monochromator #Absorption (acoustics) #Spectral line #Electron #Optics #Atomic physics #Scanning electron microscope #Transmission electron microscopy
paper · doi:10.1088/0034-4885/69/3/r04
openalex publication_date 2006/02/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/04
Electron-energy loss spectroscopy (EELS) performed using a modern transmission scanning electron microscope (STEM) now offers sub-nanometre spatial resolution and an energy resolution down to 200 meV or less, in favourable cases. The absorption spectra, which probe empty states, cover the soft x-ray region and may be obtained under conditions of well-defined momentum transfer (angle-resolved), providing a double projection onto crystallographic site and symmetry within the density of states. By combining the very high brightness of field-emission electron sources (brighter than a synchrotron) with the high cross-section of electron scattering, together with parallel detection (not possible with scanning x-ray absorption spectroscopy), a form of spectroscopy ideally suited to the study of nanostructures, interfacial states and defects in materials is obtained with uniquely high spatial resolution. We review the basic theory, the relationship of EELS to optical properties and the dielectric response function, the removal of multiple scattering artefacts and channelling effects. We consider applications in the light of recent developments in aberration corrector and electron monochromator design. Examples are cited of inner-shell spectra obtained from individual atoms within thin crystals, of the detection of interfacial electronic states in semiconductors, of inner-shell near edge structure mapped with sub-nanometre spatial resolution in glasses and of spectra obtained from individual carbon nanotubes, amongst many others.