Homogenous elemental distribution

Imaging mass spectrometry by LA-ICP-MS can be employed for studies of homogeneous element distribution in material science (e.g., in semiconductors or ceramics) for future application in the microelectronics industry. 

Amorphous Sn-, Si-, and Al-containing mixed oxides with homogeneous elemental distribution, elemental domains, and well-characterized pore architecture, including micropores and mesopores, can be prepared under controlled conditions by use of two different sol-gel processes. Sn-Si mixed oxides with low Sn content are very active and selective mild acid catalysts which are useful for esterification and etherification reactions [121]. These materials have large surface areas, and their catalytic activity and selectivity are excellent. In the esterification reaction of pentaerythritol and stearic acid catalytic activity can be correlated with surface area and decreasing tin content. The trend of decreasing tin content points to the potential importance of isolated Sn centers as active sites. 

Assuming a homogeneous element distribution in the rocks, the radiogenic production rate... 

A homogeneous elemental distribution is assumed. Theoretical values expected for the stoichiometry of the polymer. Contributions A, B, and C are defined in Table 2 above. 

In contrast to conventional micron-sized particles, the nanoscale flame-made particles do ensure a more homogeneous distribution of elements and consist of single crystallites with the desired stoichiometry. As a consequence of the more homogenous elemental distribution in flame-made titanate particles, a better performance in terms of conductivity is observed. 

The statistical nature of the homogeneity problem can be treated theoretically and it is clear that it is a matter of large numbers. Either a large number of individual particles in the investigated unit or a large number of individual analyses will produce consistent mean results, whereas the deviations from the mean (fluctuation of individual results) are an indication of the element distribution in the matrix (homogeneity). 

There are methods which are capable of showing the distribution of elements on the surface of solid samples such as soils and sediments. As such they enable one to ascertain the homogeneity of distribution of elements on the surface of and, presumably, within the portion of sample analysed. 

This is traditionally modeled as an assemblage of homogeneous elements which are described by Eq. (7), while the value of a changes. For the estimation of the distribution of a in the volume, one has to solve the equation of the excess energy transfer (the standard form of equation) ... 

When trying to characterize such solids that lack translational symmetry, one has to overcome some awkward problems known from the chemistry and physics of glasses. Presumably, their structures correspond to some random covalent network. However, no analytical tools are available that would allow a conclusive and complete determination of structures, which constitute the basis for any deeper understanding of the properties of these materials. Clearly, as a first step the chemical composition has to be determined and, moreover, the homogeneity of the element distribution has to be checked over different length scales. To gain further reliable insights into the structural features, as many different structure sensitive probes as possible have to be employed. The best way to supplement these disjunct pieces of information to obtain a fiiU... 

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