Sampling and specimen preparation

The developments in lenses and specimen preparation took almost a decade since the invention prior to the first publications on the use of electron microscopy and interpretation of micrographs for the investigation of environmental samples. The... 

In this article, the range of specimen preparation techniques is surveyed and classified to provide the reader with an appreciation of the context within which specimen preparation techniques are selected and carried out. However, it cannot provide a solution, or specific information, on the preparation technique for any particular material or sample. Successful specimen preparation, in the end, depends on the judgment, experience, and experimental skill of the preparer, and each individual specimen may present its own particular problems hence, there may be as many preparation techniques as there are materials or samples to be prepared. 

Interpretation of SEM images requires assessment of the data in the micrograph in light of both potential artifacts in imaging and specimen preparation and what is known regarding specimen properties. At the risk of being controversial, SEM imaging can be too easy. With reasonable capital expenditure, rapid sample... 

WGl (on specimen handling) is developing two standards, namely Specimen Hiindlini unci Preparation for Aiiffer Electron Spectroscopy, X-ray Photoelectron Spectro.u opy and Secondary-Ion Mass Spectrometry and Specimen Preparation. Mounting, and Analysis for Auger Electron Spectroscopy. X-ray Photoelectron Spectroscopy and Secondary-Ion Mass Spectrometry. Although from their titles the standards appear to be similar, the first is specifically for the customer, namely the scientist who supplies the. samples to the surface an-... 

Considerable difficulty was experienced in establishing the correct unit cell dimension for the nitrides and carbides of Zr and Ti. iMany different values may be found in the literature. The inconsistency in the data probably can be attributed to the existence of varying amounts of C, 0, or X in the samples. Table 21-1 gives the parameters determined bj a number of investigators. The values of ao used in this research were those given by Duwez and Odell [1]. These compared favorably with the values found on test specimens, powdered compact samples, and ZrX prepared by heating Zr in purified X2 at 1000°C for 20 hr. 

Interpretable high-resolution structural infomiation (e.g. preservation of dimensions, or correlation of the stmctiiral detail with a physiologically or biochemically controlled state) is therefore obtained exclusively from samples in which life has been stopped very quickly and with a sufficiently high time resolution for the cellular dynamics [19]. Modem concepts for specimen preparation therefore try to avoid traditional, chemical... 

The infonuation that can be extracted from inorganic samples depends mainly on tlie electron beam/specimen interaction and instrumental parameters [1], in contrast to organic and biological materials, where it depends strongly on specimen preparation. 

Two checks of the accuracy of the determinations of the lattice constants were made. Filings of samples 2 and 3 were placed in capillary tubes of two different diameters, and photographs were made and interpreted. For each sample the same lattice constant was obtained from the two photographs. For samples 11 and 14 filings were prepared from two different portions of the 25 g. sample, and powder photographs were prepared. In the case of specimen 11 the lattice constant determined from the two preparations was the same, whereas for specimen 14 values differing by 0-0055 A were obtained. We believe that the latter variation is due to a small difference in composition, perhaps 0-5 %, in the two samples the lattice constant is very sensitive to composition in this region. 

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