Electron Diffraction and Transmission Electron Microscopy

Structural fingerprinting in the transmission electron microscope: overview and opportunities to implement enhanced strategies for nanocrystal identification

“…Quite analogously, there has been a proposal to use the visual appearance of HRTEM structure images 6 from homologous series or isomorphic structures for fingerprinting purposes [73]. Such structure images need to be recorded at the Scherzer (de)focus from weak phase objects under strictly optimized conditions (preferentially including an objective-lens aperture that blocks all diffracted beam with spatial frequencies beyond the first zero crossing of the microscope's phase contrast transfer function) that make the appearance of the image essentially independent of the operation parameters of the TEM.…”

“…Quite analogously, there has been a proposal to use the visual appearance of HRTEM structure images 6 from homologous series or isomorphic structures for fingerprinting purposes [73]. Such structure images need to be recorded at the Scherzer (de)focus from weak phase objects under strictly optimized conditions (preferentially including an objective-lens aperture that blocks all diffracted 638 P. Moeck and P. Fraundorf 5 The beam convergence in convergent beam electron diffraction (CBED) effectively expands the diffraction spots into diffraction disks with crystallographically distinct fine structure.…”

Magnetic Imaging and Microscopy

“…Furthermore, the application of magnetic fields during imaging is often severely limited due to their deflecting and depolarizing effects on the electrons, although there are sometimes strategies to partially overcome this [16]. Here, we focus on methods which use an unpolarized electron beam as the probe; however, we note that certain specialized approaches such as spin-polarized low-energy electron microscopy employ polarized electron beams to excite the sample, details of which can be found in [9,17,18].…”