This book (Practical Electron Microscopy and Database) is a reference for TEM and SEM students, operators, engineers, technicians, managers, and researchers.
|
=================================================================================
Recording atomic-resolved images of small clusters is not an easy task, and the 3-D (three-dimensional) determination of atomic structure of nanoclusters is even more challenging. The intrinsic instability of the clusters limits the duration of the TEM observation and the electron beam dosage that can be used. To obtain 3-D information, one needs to take focal series of TEM images in combination with exit wave image reconstructions. [2,3] This method still requires that the nanoclusters stay on the support more than tens of seconds during observation, but this is not applicable for most of small clusters under normal imaging conditions. Electron tomography is capable for 3-D information but again requires a series of images to be taken in different specimen orientations. [4,5]
Although the computational correction of the phase error caused by coma requires the determination of only a small number of parameters, it is harder to determine the values of these parameters from imaging single particles than from imaging 2-D (two-dimensional) crystals [1].
[1] Henderson, R., Baldwin, J.M., Downing, K.H., Lepault, J., Zemlin, F., 1986. Structure of
purple membrane from halobacterium-halobium – recording, measurement and evaluation of electron-micrographs at 3.5 Å resolution. Ultramicroscopy 19,
147–178.
[2] Op de Beeck M, Van Dyck D. Ultramicroscopy 1996;64:153–65.
[3] Op de Beeck M, Van Dyck D, Coene W. Ultramicroscopy 1996;64:167–83.
[4] Midgley PA, Dunin-Borkowski RE. Nat Mater 2009;8:271–80.
[5] Gonza´lez JC, Herna´ndez JC, Lo´pez-Haro M, del Rı´o E, Delgado JJ, Hungrı´a AB, et al. Angew
Chem 2009;121:5417–9.
|