Target preparation intermetallic targets

In many cases, direct reaction of the elements is not always feasible, especially when the physical characteristics for the constituents (melting point, vapor pressure, diffusion coefficients, etc.) or kinetics of the reaction are unfavorable, or if the target product is thermodynamically metastable (in such cases, other synthetic routes discussed elsewhere in this chapter may be more effective). Nevertheless, direct reaction of the elements or preformed preciu-sors has to date been the most commonly used approach to prepare intermetallic clathrates, producing the largest variety of compositions synthesized to date (cf. Table 3.1 for representative reactions). 

Usoltsev, I., Eichler, R., Dressier, R., Piguet, D., Wittwer, D., Turler, A., Brutsch, R., Olsen, E.A., Omtvedt, J.P., Semchenkov, A. Preparation of Pd-based intermetallic targets for high intensity irradiations. Nucl. Instrum. Methods Phys. Res., Sect. A 691, 5-9 (2012)... 

Various synthesis routes to intermetallic clathrates have been successfully applied covering the whole spectrum of preparation methods in sohd state chemistry. The applicabihty of each method is dependent on the elements forming the target material and some thermodynamic properties, such as formation energy and vapor pressure of components at the reaction temperature. Although it is straightforward for many systems to prepare a clathrate phase at one certain composition. 

As shown in this article, intermetallic compounds are not rare species in catalysis. They are quite often formed on conventionally supported catalysts by subjecting them to reducing conditions—either during the preparation or under reaction conditions— thus being present in a broad range of reactions and catalytic systems. Complementarily, a number of methods are known for the targeted... 

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