Development of a high energy resolution electron energy‐loss spectroscopy microscope

Abstract

We have developed a high energy resolution electron energy-loss spectroscopy (EELS) microscope, which can take spectra from specified small specimen areas and specified small reciprocal space areas to investigate detailed electronic structures. The EELS microscope is equipped with retarding Wien filters as the monochromator and the analyser. The filters are designed to achieve a stigmatic focus. The energy resolutions are 12 meV and 25 meV for cases without and with a specimen, respectively. Spatial and momentum resolutions are 30-110 nm in diameter and 1.1 nm-1 in angular diameter, respectively. EELS spectra are presented to show the performance of this instrument.

High-energy-resolution monochromator for aberration-corrected scanning transmission electron microscopy/electron energy-loss spectroscopy

“…In practice, the dispersing-undispersing design preserves about a factor of three times higher brightness than simpler designs that do not cancel the energy dispersion in the beam incident on the sample. Two of the above monochromators are used together with Wien filter spectrometers that are preceded by electron decelerators, and act on electron beams whose energy has been reduced to a few hundred electron volts (Terauchi et al 1999;Batson et al 2000). The same high-voltage power supply is used for the deceleration as for the microscope's accelerator.…”

Optoelectronic Properties of InAlN/GaN Distributed Bragg Reflector Heterostructure Examined by Valence Electron Energy Loss Spectroscopy

“…can be as small as a few angstroms on the sample and can be successfully combined with monochromated electron energy loss spectroscopỹ EELS! that can achieve an energy resolution down to ;0.1 eV~Terauchi et al., 1991;Batson, 2005; In general, EELS assesses the energy loss of inelastically scattered electrons that pass through the sample in the transmission electron microscope~TEM!. Valence-EELS @~V!EELS# centers itself on the lower energy loss~low-loss!…”

Analytical transmission electron microscopy at organic interfaces

“…Ivory EELS [2] Enamel (damaged) EELS [1] Enamel (undamaged) EELS [1] [32], we calculate that approximately 95% of the carbon atoms in mineralised bone will be present in collagen. This conclusion is supported by the observed opposite periodic trend of elemental C compared to Ca, P and O along mineralised collagen, in both ivory dentine (see figure 3) [15] and mouse bone [14], which is consistent with the majority of carbon being located outside of the mineral component.…”

“…Recent instrumental advances in the transmission electron microscope (TEM) include aberration correctors for improved electron optics, as well as monochromators [1] which reduce the energy spread of the electron beam. These allow the formation of smaller (sub-angstrom) electron probes, and the resolution of finer (>100 meV) energy features in electron energy-loss spectra (EELS), respectively.…”