High-resolution electron microscopy, images

Chems et al [18] performed a detailed quantitative analysis of CBED data for (1010) inversion domains in GaN grown on sapphire and concluded that of the various structural models tested, only the IDB model [14] was consistent with their data. High resolution electron microscopy images [16,20] also support the IDB model. Such images show a shift in intensity of lattice fringes across the (1010) plane that is consistent with the proposed model. 

Banfield, J. R, D. R. Veblen, and D. J. Smith. 1991. The identification of naturally occurring Ti02 (B) by structure determination using high-resolution electron microscopy, image simulation, and distance-least-squares refinement. AwtencowAfmera/ogwf 76, no. 3-4 343-353. 

There are three primary image modes that are used in conventional TEM work, bright-field microscopy, dark-field microscopy, and high-resolution electron microscopy. In practice, the three image modes differ in the way in which an objective diaphragm is used as a filter in the back focal plane. 

A special mention is in order of high-resolution electron microscopy (HREM), a variant that permits columns of atoms normal to the specimen surface to be imaged the resolution is better than an atomic diameter, but the nature of the image is not safely interpretable without the use of computer simulation of images to check whether the assumed interpretation matches what is actually seen. Solid-state chemists studying complex, non-stoichiometric oxides found this image simulation approach essential for their work. The technique has proved immensely powerful, especially with respect to the many types of defect that are found in microstructures. 

D. van Dyck, High resolution electron microscopy, Advances in Imaging and Electron Physics 123 (2002) 105... 

MA O Keefe, P Buseck, S Ijima. Computed crystal structure images for high resolution electron microscopy. Nature 274 322 - 324, 1978. 

FS Han, HF Fan, FH Li. Image processing in high-resolution electron microscopy using the direct method. II. Image deconvolution, Acta Cryst. A42 353-356,1986. 

JJ Hu, FH Li. Maximum entropy image deconvolution in high resolution electron microscopy. Ultramicroscopy 35 339-350, 1991. 

If a fiber is less than a few micrometers thick, mineralogists may emphasize its fineness with the term fine-fibrous. Particles with diameters of a few mils (1 mil = 25 micrometers see Table 1.1) must be examined under a microscope. Electron microscopy is employed for the finest materials, and high-resolution electron microscopy is required to image fibrils with diameters of a few angstroms (1 angstrom = 10 ° meter or 0.1 of a nanometer). At any resolution, the aspect ratio can be estimated or measured as part of the identification of the fiber. 

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