Positron microscopy

Figure 4.55 Comparison of defect imaging by a cathodoluminiscence and b SEM versus pictures obtained using positron microscopy in Munich...

Figure 4.56 Explanation of a positron annihilation lifetime technique based on positron microscopy for studying vacancy-type defects as a function of material depth [192]...

Auger Electron Spectroscopy Electron Microprobe Analysis of Minerals Imaging Optics Particle Size Analysis Positron Microscopy Scanning Electron Microscopy... 

Electron Microprobe Analysis of Minerals Microscopy Scanning Electron Microscopy Surface Chemistry Positron Microscopy Transmission Electron Microscopy X-Ray Analysis X-Ray Photoelectron Spectroscopy... 

PACS PCA PDB PEEM PESTM PET PrP Picture Archiving and Communication Systems Principal Component Analysis Protein Data Bank Photoemission Electron Microscopy STM Photoemission Spectroscopy Positron Emission Tomography Prion Protein... 

At the same time investigations using light scattering, electron microscopy, positron annihilation, dielectricity and transport properties 30,- ) indicated the surfactant molecules not to be Involved in associations to colloidal size aggregates at these low water contents. The low light scattering intensity rather points to the surfactant molecules not to be inter-associated (Fig. 7). 

To understand the importance of nanostructures in microsieving membranes, the basic structure of nanophased ceramics must be briefly described. Because the particles are extremely small, one to a few tens of nanometers, an important fraction of the atoms is found in or very near the interface between grains, as reported in Table 2 [32]. Figure 11 is a schematic representation of a nanophase material. One can see that individual grains in the 5 nm range induce a biphasic material with an interfacial phase between the grains and a residual nanoporosity, evidenced by positron lifetime spectroscopy [33]. Transmission electron microscopy is also a well-adapted technique for nanoscale structure characterization, as illustrated later. 

At this point, we shall not treat further methods for the investigation of defects in crystals, such as e.g. electron microscopy, for which one requires crystals with a thickness of less than 5000 A, or positron annihilation. In any case, a careful analysis of the quality of the crystal to be investigated belongs among the indispensable operations which must be carried out in studying molecular crystals. 

The structure of PEMs, in particular their phase-separated morphology at nm-scale, has been studied with a number of experimental techniques, including small- and wide-angle X-ray and neutron scattering, infrared and Raman spectra, time-dependent FTIR, NMR, electron microscopy, positron annihilation spectroscopy, scanning probe microscopy, and scanning electrochemical microscopy (SECM) (for a review of this literature see [31]). Structural studies of PEMs have mainly focused on Nafion. A thorough recent review on this particular membrane is provided in [32]. 

W.J. Phythian, N. de Diego, J. Mace and R.J. McElroy, Characterisation of model Fe-Cu-Mn-Ti-N alloys by electron microscopy and positron... 

In the development of a new correlation method, microstructural characterization of the surveillance materials of some PWR plants was also performed in order to understand the embrittlement mechanism of RPV steels with different Cu contents. At the same time, another test reactor irradiation project, the PLIM project, was also conducted by Japan Nuclear Energy Safety (JNES), where extensive microstructural characterization of base metals and weld metals with a wide range of chemical compositions in terms of Cu and Ni was performed using APT, transmission electron microscopy and positron annihilation to obtain new insights with the embrittlement mechanism at high fluences.The mechanism of embrittlement identified or confirmed in these projects was summarized as follows ... 

The structure of glassy quartz and various modifications of crystalline quartz has been studied in detail by direct structure-sensitive technique X-ray diffraction analysis, positron annihilation and electron microscopy. 

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