This article describes electron energy-loss spectroscopy (EELS), energy-filtering transmission electron microscopy (EFTEM) and electron spectroscopic diffraction (ESD) in a transmission electron microscope (TEM) or in a scanning transmission electron microscope (STEM) as versatile tools used in many areas of materials science, physics, chemistry, and biology with high spatial resolution up to the atomic level. Measuring the energy and angular distributions of electrons passing through thin specimens, EELS can provide structural and chemical information about the broad range of electron excitations in the materials (surface and volume plasmons, excitons, phonons), electronic properties (densities of state, interband transitions, bandgaps), optical properties, elemental compositions, bonding, coordination, thickness, etc. Utilizing imaging properties of a magnetic field produced between prism-shaped polepieces, stationary-beam EFTEM expands EELS into two dimensions and enables to display magnified images and sets of images (image spectrum) or diffraction patterns at a selected energy loss (ESD). In STEM, an entire EEL spectrum can be acquired at any and each pixel of an image, producing ultimately a three-dimensional dataset (spectrum image). Basic physical principles of EELS, EFTEM, ESD, S/TEM-EELS spectrum image, EFTEM-image spectrum, EFTEM/EELS tomography and recent developments in instrumentation, methodology and in situ applications are discussed.
the Chemistry, Molecular Sciences and Chemical Engineering Module of the Encyclopedia of Analytical Science, 3rd Edition
ELECTRON ENERGY-LOSS SPECTROSCOPY AND IMAGING, the Chemistry, Molecular Sciences and Chemical Engineering Module of the Encyclopedia of Analytical Science, 3rd Edition
(Accessed June 9, 2023)