Synthesis and crystal growth

Previous results of the preparation chemistry of actinide elements have been reviewed in detail by F. WeigeF In the following chapter, the actual state of the possibihties for the preparation and refining of actinide metals will be described the principles and trends in synthesis and crystal growth of (simple) actinide compounds will be shown. 

Therefore, and to avoid possible reactions with the quartz wall, it was attempted to combine synthesis and crystal growth of actinide pnictides in a modified van Arkel process Actinide metal or carbide - the latter obtained by carboreduction of the oxide - are heated in the presence of the pnictogen and of the transporting agent at the... 

While this chapter has focussed on synthesis of polycrystalline samples, other aspects of the bismuth and thallium cuprate superconductors are discussed elsewhere. An introduction to synthesis and crystal growth is given in Chapter 5, and a review of the crystal chemistry of the two families is presented in Chapter... 

Due to the difficulties in synthesis and crystal growth, which are greater for InN than for other compounds of this family, and to the fact that the present industrial interest and economic expectations are much lower, the number of experimental results concerning the mechanical properties is quite small. Therefore, there are also far fewer theoretical studies than for the sister compounds. All studies are summarised in TABLE 7. 

Combined Synthesis and Crystal Growth (a) Solution Reaction Procedures... 

High-temperature chemical-transport reactions afford a convenient means for the synthesis and crystal growth of a wide... 

Montgomery, L. K. Chemical Synthesis and Crystal Growth Techniques. In Organic Conductors Fundamentals and Applications Farges, J.-P., Ed. Marcel Dekker New York, 1994 Vol. 4, pp 115-145. 

The separation of the products is not easy, although not impossible. For the exploration of the respective systems and their phase contents, it is, however, often not necessary to obtain pure products because modem, fast X-ray crystallography is an easy means to analyze even multiproduct reactions. Afterward, when the respective compounds are known, care has to be taken to produce the new compounds as pure phase by whatever route is desirable. One major advantage of the metallothermic reduction route is the fairly low reaction temperatures as these allow for the synthesis and crystal growth of compounds that decompose in the solid state, melt incongmently, or even form and decompose in the solid state at fairly low temperatures. Also, low-temperature modifications may be grown as single crystals below the transition temperature. 

Fig. 1. Segmented cx>ld crucibles for synthesis and crystal growth (a) cold boat, (b) Hukin crucible.

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