Atomic Imaging of particle

MARKS AND SMITH Atomic Imaging of Particle Surfaces... 

Fig. Vni-3. (a) Atomic force microscope (AFM) and (b) transmission electron microscope (TEM) images of lead selenide particles grown under arachidic acid monolayers. (Pi Ref. 57.)...

Figure 4.15. Atomically resolved TEM images of a Cu/ZnO model catalyst in various gas environments together with the corresponding Wulff construction of the Cu particle (a,b) Cu nanocrystal faceted by (100), (110) and (111) surfaces the TEM image was recorded at 1.5 mbar of H2 at 220 °C with the electron beam parallel to the [Oil] zone-axis of copper. The insert shows EELS data at the Cu L2,3-edge...

Fig. 11 Formation of crystalline 3D super-lattices of tin nanoparticles a TEM view of a facetted super-crystal b SEM image showing particles included into a super-crystal as well as the organic surrounding c High resolution micrograph showing the alignment of the tin atomic planes inside the super-structure...

The TEM images of alfalfa shoots (Figure 6a) and the EDS analysis (Figure 6b) show that Au atoms were dispersed through the longitudinal axis of alfalfa seedlings. EDS was performed on many particles to corroborate that all of them were pure gold. 

Since ion beams (like electron beams) can be readily focussed and deflected on a sample so that chemical composition imaging is possible. The sputtered particles largely originate from the top one or two atom layers of a surface, so that SIMS is a surface specific technique and it provides information on a depth scale comparable with other surface spectroscopies. 

ETEM is thus used as a nanolaboratory with multi-probe measurements. Design of novel reactions and nanosynthesis are possible. The structure and chemistry of dynamic catalysts are revealed by atomic imaging, ED, and chemical analysis (via PEELS/GIF), while the sample is immersed in controlled gas atmospheres at the operating temperature. The analysis of oxidation state in intermediate phases of the reaction and, in principle, EXELFS studies are possible. In many applications, the size and subsurface location of particles require the use of the dynamic STEM system (integrated with ETEM), with complementary methods for chemical and crystallographic analyses. 

Reflection contrast Reflection-imaging microscopy Field ion microscopy Quantification in gap between light and em microscopies Useful for imaging highly reflective particles such as silver grains in autoradiographs Atomic structure of crystals Immunoelectron Localization of cellular antigens... 

Cover Illustration Atomic force microscopy image of molybdenum oxide particles on flat, silicon dioxide substrate, which serves as a model system for a supported catalyst. The area shown corresponds to one square micrometer the maximum difference in height is approximately 10 nanometer. The superimposed curve is the secondary ion mass spectrum of the model catalyst, showing the caracteristic isotopic patterns of single molybdenum ions and of molybdenum oxide cluster ions. 

The modern methods of high resolution can be applied to the study of small metallic particles. The most usefull technique is perhaps the projected potential images (1/7). Fig. 15 shows an image of a gold particle with icosahedral shape. Atomic resolution along the ill planes is observed. The continuity of the planes along the boundary is clearly seen. 

Atomic Number Imaging of Supported Catalyst Particles by Scanning Transmission Electron Microscope... 

TREACY Atomic Number Imaging of Catalyst Particles... 

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