Transmission electron microscopy microstructure

Thiel, B.L., Kunkel, D.D., Viney, C. Physical and chemical microstructure of spider dragline a study by analytical transmission electron microscopy. Biopolymers 34 1089-1097, 1994. 

The length and the diameter of MWCNT can be measured directly by TEM. From high-resolution transmission electron microscopy (HRTEM) images exhibiting oo.l fringes follows the number of coaxial tubes and possibly the microstructure of the caps in MWCNT, as viewed along the incident electron beam [24], Also anomalous intercylinder spacings and defects are revealed in this way [1,11]. 

The crystallization of glassy Pd-Ni-P and Pd-Cu-P alloys is complicated by the formation of metastable crystalline phaf s [26]. The final (stable) crystallization product consists of a mixture of a (Pd,Ni) or (Pd,Cu) fee solid solution and more than one kind of metal phosphide of low crystallographic symmetry. Donovan et al. [27] used transmission electron microscopy (TEM) and X-ray microanalysis to study the microstructure of slowly cooled crystalline Pd4oNi4oP2o- They identified the compositions of the metal phosphides to be Pd34Ni45P2j and Pdg8Ni[4Pjg. 

The picture of cement microstructure that now emerges is of particles of partially degraded glass embedded in a matrix of calcium and aluminium polyalkenoates and sheathed in a layer of siliceous gel probably formed just outside the particle boundary. This structure (shown in Figure 5.17) was first proposed by Wilson Prosser (1982, 1984) and has since been confirmed by recent electron microscopic studies by Swift Dogan (1990) and Hatton Brook (1992). The latter used transmission electron microscopy with high resolution to confirm this model without ambiguity. 

Transmission electron microscopy (TEM) is a powerful and mature microstructural characterization technique. The principles and applications of TEM have been described in many books [16 20]. The image formation in TEM is similar to that in optical microscopy, but the resolution of TEM is far superior to that of an optical microscope due to the enormous differences in the wavelengths of the sources used in these two microscopes. Today, most TEMs can be routinely operated at a resolution better than 0.2 nm, which provides the desired microstructural information about ultrathin layers and their interfaces in OLEDs. Electron beams can be focused to nanometer size, so nanochemical analysis of materials can be performed [21]. These unique abilities to provide structural and chemical information down to atomic-nanometer dimensions make it an indispensable technique in OLED development. However, TEM specimens need to be very thin to make them transparent to electrons. This is one of the most formidable obstacles in using TEM in this field. Current versions of OLEDs are composed of hard glass substrates, soft organic materials, and metal layers. Conventional TEM sample preparation techniques are no longer suitable for these samples [22-24], Recently, these difficulties have been overcome by using the advanced dual beam (DB) microscopy technique, which will be discussed later. 

Kohlstedt D. L. and Vander Sande X B. (1973). Transmission electron microscopy investigation of defects microstructure of four natural orthopyroxenes. Contrib. Mineral. Petrol, 42 169-180. 

The kinetic behavior and microstructure of citrus pectin gels in 60% Sucrose were investigated by transmission electron microscopy (TeM). Ca + addition at Ph 3.0 resulted in faster gel formation. (Adapted from Lofgren et ah, 2005)... 

The most significant advantage of these more quantitative methods is that, in a binary system, only one sample is needed to determine the position of both phase boimdaries in a two-phase field. Further, if the alloy lies in the two-phase field over a wide range of temperatures, it is feasible that only one alloy need be used to fix the phase boundaries over this range of temperature. In a ternary system the analogous position is found with three-phase fields and, as these also define the limiting tie-lines of the three sets of two-phase fields, substantial information can be gained from the accurate determination of only one alloy. More recently transmission electron microscopy (TEM) has been used which is particularly valuable when microstructures are very fine as, for example, found in yTiAl alloys (Chen et al. 1994). 

Some examples of ternary alloy precursors are also shown. Their general properties were examined and their microstructures were directly observed by transmission electron microscopy. Thus, catalysts synthesized from multi-system alloys had high solubility of additional elements into a major element, and might be expected to work as new catalysts. 

Daulton, T. L., Bematowicz, T. J., Lewis, R. S. et al. (2003) Polytype distribution in circumstellar silicon carbide Microstructural characterization by transmission electron microscopy. Geochimica et Cosmochimica Acta, 67, 4743-4767. 

FIG. 1.13 Spherical and cubic model particles with crystalline or amorphous microstructure (a) spherical zinc sulfide particles (transmission electron microscopy, TEM, see Section 1.6a.2a) x-ray diffraction studies show that the microstructure of these particles is crystalline (b) cubic lead sulfide particles (scanning electron microscopy, SEM, see Section 1.6a.2a) (c) amorphous spherical particles of manganese (II) phosphate (TEM) and (d) crystalline cubic cadmium carbonate particles (SEM). (Reprinted with permission of Matijevic 1993.)... 

The properties and performance of cemented carbide tools depend not only on the type and amount of carbide but also on carbide grain size and the amount of binder metal. Information on porosity, grain size and distribution of WC, solid solution cubic carbides, and the metallic binder phase is obtained from metallographically polished samples. Optical microscopy and scanning and transmission electron microscopy are employed for microstructural evaluation. Typical microstructures of cemented carbides are shown in Figure 3. 

Optical microscopy and scanning and transmission electron microscopy are employed for microstructural evaluation. Typical microstructures of cemented carbides are shown in Figure 2.4. Among the physical... 

The microstructure of several of these thin films was studied extensively, using Transmission Electron Microscopy (T.E.M.). These T.E.M. observations together with X-ray Energy Dispersion Spectroscopy (E.D.S.) as well as usual X-ray spectra show that the films are highly homogeneous and have essentially a single YBCO (123) phase. 

The advances that have achieved so far are mainly based on increasing understanding of processing and microstructure/property relationship. New analytical methods and high resolution transmission electron microscopy have provided new insight into the grain boundary region and offer the possibility to tailor the microstructure for specific applications. 

Microstructures of (1) PE-g-PPG polymer hybrid and (2) the blended sample of PE and PPG were observed by transmission electron microscopy (TEM) images after the preparation of press sheets of each polymer sample at 200 °C. The TEM images of the resulting polymer hybrid reveal the nanometer level microphase-separation morphology between the PE segment and the PPG segment compared with the PE/PPG blended polymer. From the result, the nanodispersion of different segments in polymer hybrids is possible, but different from the blended polymer sample (Fig. 8). 

M. Natan, S.W. Duncan. Microstructure and growth kinetics of CrSi2 on Si 100 studied using cross-sectional transmission electron microscopy // Thin Solid Films. -1985.-V.123, No.l.-P.69-85. 

---