Micro-diffraction

Figures 4c and 4d illustrate what happens when the incident electron probe is focused to illuminate alternately a crystallite in the center of the image (labelled twin) (Figure 4c) and another crystallite adjacent to the twin (Figure 4d). This focused-probe technique is sometimes referred to as micro-diffi-action. Two effects are evident in these micro-diffraction patterns. First, the diffraction patterns consist...

Takiyama, K. (1959a) Formation and aging of precipitates. X. An electron micro-diffraction study on crystal habit of barium sulphate precipitates. Bull Chem. Soc. Japan, 32, 68-70. 

Figure 2.8. Scanning electron microscopy (SEM) photomicrographs of (a) a micro-diffractive optical element mold fabricated by a focused ion beam (FIB) and (b) the transferred optical element on a sol-gel film. [Reprinted with permission from Ref. 98.]... 

Phase quadrature is an over-arching concept for all interferometric detection. However, achieving a common-path configuration that locks in a stable quadrature condition puts constraints on possible system designs. This section reviews the several configurations of common-path quadrature that have been demonstrated so far in spinning-disc systems. These are the micro-diffraction class, the adaptive optical class, the phase contrast and the in-line class. At the end of this section, we show that the phase-contrast and in-line classes are conjugate quadratures of each other. 

In the present paper non-conventional TEM methods to characterize small metallic particles are presented. The topographic information on the particles shape can be combined with micro-diffraction (using STEM) data to obtain a full characterization of the particle. The case of gold particles evaporated on a NaCl substrate is used as example. The particle shapes observed are discussed. It is shown that many particles have a crystal structure which is different from the bulk (Fee). 

Figure 5. Micro-diffraction pattern of square gold particle showing splitting of the spots.

In Fig. 10 the micro-diffraction patterns of I5 and D5 particles are shown. These patterns are identical to the ones calculated by Yang et al. (1 1) based on the non-Fcc model. This type of particles is a very important example of departures from the Fee bulk symmetry. In addition is also an example of pol i hedral particles formed by several units. 

Dillmann, P., Neff, D., Mazaudier, F., et al. (2002). Characterisation of iron archaeological analogues using micro diffraction under synchrotron radiation. Application to the study of long term corrosion behaviour of low alloy steels. Journal de Physique IV12 393 408. 

An ongoing study of sulfur materials taken from an Icelandic Norse-trading site context (55) has used this combination of simultaneous co-incident X-ray micro-fluorescence and micro-diffraction analyses. The compositional data from the fluorescence results are used to constrain the multi-phase analysis of the diffraction data. This approach reduces the requirement for accuracy in the... 

Electromicroscopic analysis of the samples showed the presence of finely dispersed platinum particles on the catalyst surface (d.v5 g6=l 0-12 A) large particles (d=20-35 A) were observed very rarely. These catalysts did not give micro-diffraction images. 

The atomic structure of the carbon deposited was studied by TEM using a JEM-IOOC electron microscope in the micro-diffraction mode. The structure of the carbyne crystals is analyzed by atomic force microscopy (AFM). The images are obtained by contact mode. The film thickness was determined from SEM observations of the film cross sections. 

In a subsequent study by Kreger, a micro-diffraction technique was... 

Fig. 3.5. A schematic diagram of the McMullan PEELS acquisition system currently in operation (courtesy of Dr C. Walsh). Simple switching of the post-quadrupole deflection coil can direct the transmitted electrons to separate detectors to form a bright field image as well as a two-dimensional micro-diffraction image respectively.

Powder x-ray diffraction (XRD), emission spectrum analysis, electron microscopy (EM) with micro-diffraction, BET, UV-visible diffuse reflectance spectroscopy, temperature-programmed desorption of O2 (TPD), temperature-programmed reduction with... 

Fig. 6 Illustration of the common characteristics of powder diffraction patterns collected with micro-XRD. Notice that the individual spots are from larger, micron-sized crystallites while the spotted rings are indicative of micro-crystalline particles (a). The spottiness of the rings is an indication of insufficient number of grains in the dif aetion volume of the sample. The continuous rings indicate that all lattice planes hkl are simultaneously present in all orientations relative to the incident X-ray beam. In micro-diffraction with spot sizes on the micron-scale this usually occurs only with nanocrystalline particles (b)...

Any regions of the sample under the incident beam (usually a few pm diameter) exhibiting crystallinity, will diffract electrons away from the central spot, forming a diffraction pattern observable at the back focal plane of the objective lens. Like X-ray diffraction, this can provide identification of crystalline phase, orientation, and lattice parameters. In micro-diffraction, the incident beam is focused down to sub-micron areas, but this focusing degrades the diffraction pattern. 

Nishiyama N., Tanaka S., Egashira Y., Oku Y., Ueyama K. Vapor-phase s)mthesis of mesoporous silica thin films. Chem. Mate. 2003 15 1006-1011 Noma T., Takada K., Miyata H., lida A. X-ray micro diffraction study on mesostructured silica thin films. Nucl. Instrum. Methods Phys. Res. A 2001 467 1021-1025 Ogawa M. Formation of novel oriented transparent films of layered silica-surfactant nanocomposites. J. Am. Chem. Soc. 1994 116 7941-7942... 

Figure 8. The micro-diffraction patterns can be obtained from the small regions.

Micro-Diffraction and Micro-Analysis of the Cycled Cathode Particles... 

Figure 8 demonstrates the micro-diffraction patterns of these BU, NS, and SE small regions and the structure information of these regions may obtain. 

To describe the electrochemical lithiation of the layered oxysulfide Sr2Mn02Cu3.5S3 Roberts et al. [65] have used micro-diffraction in combination... 

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