Growth of Single Crystals

We will now describe the growth of single crystals. That is, how single crystals are obtained. It will become apparent that most single crystcils are obtained from a melt of the material desired. Although many melt-growth methods were proposed and tried in the past, only a few have survived to the present and are in use. 

Obviously, the major difference in the single-crystal and polycrystalline (crystallite) state is a matter of size. For the single-crystal, the size is large ( 10 cm), whereas in the polycrystalline state, the size of the crystals is small (10 nm = 0.001 cm.) The methods for obtaining one or the other differ considerably. They include formation and growth from  

If we are to grow a single crystal, we will need some sort of furnace, which is simply a closed space, heated by electriccd elements wherein the internal temperature is controlled. 

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The process of sintering by vapour phase transport is probably important to the growth of single crystals of solids from polycrystalline samples in a closed system, where the vapour species are the transporting gas, which may have the same or different chemical composition from die solid. An example where... 

Growth of single crystals. Crystals of the aluminum selenide halides (needles, maximum length 15 mm) were grown by vapor transport in sealed ampoules between two temperatures (380 and 320°C for Al-SeCl, and 350 and 300°C for AlSeBr and AlSel) over a period of two months. A large excess of the halogenide was used (266). 

Growth of single crystals. Single crystals of the selenide and tel-luride halides can be grown by recrystallization at 360-390°C, or sublimation at 420 (InSeCl) and 370°C (InTel), respectively (162). 

A halide flux enhances the growth of single crystals of intermetallic compounds such as CaNi, and compounds in the Dy-Mg and Ce-Mg " systems which have... 

The most critical element in melt-growth of single crystals is the container, or crucible. The first requirement for selection of a suitable crucible is that the crucible does not react with the melt. The second is... 

In these cases, one is limited to the growth of single crystals of the transition metals since it is those metals which form volatile carbonyl compounds. The alkali metals, alkaline earth metals and certain of those elements which are allotropic in nature are not at aH suited for this type of crystal growth. 

Solvothermal growth of single crystals or poly crystalline aggregates from hydro-thermal or ammonothermal solution. 

Metal powders can readily react with alkali metal polychalcogenide melts at typical temperatures in the range 200 600°C to afford chalcogen-rich complexes. As discussed in an excellent review article,10 the highly ionic nature of the melt greatly enhances the solubility of the chosen metal and often facilitates the growth of single crystals. 

Duan, X. Lieber, C. M. 2000. Laser-assisted catalytic growth of single crystal GaN nanowires. J. Am. Chem. Soc. 122 188-189. 

High-temperature liquid intermetallic solution growth of single crystals and quasicrystals... 

In a paper by Fisk and Remeika (1989) several points concerning the growth of single crystals from metal fluxes have been discussed. Attention has been dedicated to various aspects of the problem of separating crystal and flux, for which two main approaches, chemical and mechanical, may be considered. The following examples drawn from the preparative chemistry of the rare earth alloys were described. 

Fisk, Z. and Remeika, J.P. (1989) Growth of single crystals from molten metal fluxes. In Handbook on the Physics and Chemistry of Rare Earths, eds. Gschneidner Jr., K.A. and Eyring, L.R. (North Holland, Amsterdam), Vol. 12, p. 53. 

Laudice, R. A. The growth of single crystals (Prentice-Hall, Englewood Cliffs, N.J., 1970). 

Unfortunately, a transition from the a phase of Np metal to the P phase occurs at the low temperature of 301 K, making the growth of single crystals of a-Np metal extremely difficult. 

In this chapter, preparation and purification methods are reviewed. In view of the expected role of 5 f electrons in the metallic bond of actinides, methods for the preparation of metals have been particularly studied. There has also been important progress in the preparation of simple binary compounds. Special emphasis has been given to the growth of single crystals, particularly needed for the most refined physical techniques. 

Compounds can be prepared either in polycrystalline form, often referred to as ceramics, or as single crystals. The synthesis of oxides in polycrystalline form is typically straightforward relative to single crystal growth. For the growth of single crystals of complex oxides, a unique growth system appropriate to the chemistry and... 

R. A. Laudise, "The Growth of Single Crystals , Prentice-Hall, NJ, 1970. 

Considerable effort has been expended in growing single crystals of compositions in the solid solution, with particular emphasis on the superconducting composition. A variety of methods have been employed, all flux type, as the solid solution members are not congruently melting. There have been a few detailed reports on growth of single crystals from melts in the... 

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