It is well known that, single crystal grow at specific temperature called "growth temperature". Is it the unique temperature for growing this crystal or we can grow it at other temperatures but with less growth rate ?
Dear Abduh Mohammad Abdulwahab ,
Temperature plays a role in crystallization.
The solubility is crucial as well. At a specific temperature, if the solubility of the desired phase increases, the crystallization would be hard to occur.
Hard to get good size and shaped crystals.
You may precipitate the crystals in a specific solvent mixture at different temperatures. It works if the solubility is affected in a lower range.
For some system, literature is showing different phases at different temperatures.
I suggest carefully checking your system to avoid the crystallization of a secondary phase, a solvate, or even an undesirable polymorph of your interest.
Best regards,
WNM
Single crystal grow at different temperatures which depends up on the solubilty of the compd. in a solvent. Compd. must be soluble by heating and on cooling slowly the crystallization takes place some times at room temperature or lower temp. at zero deg. Highly soluble compds. crystallize on making their saturated solution like sugers and inorganic water soluble salts.
Dear Abduh Mohammad Abdulwahab this is a very interesting and important technical question. Virtually every synthetic chemists now and then faces the problem of growing single crystals. Personally, we have 40+ years of experience in growing single-crystals of organometallic compounds for X-ray diffraction studies. In my experience there is no such thing as a universal "growth temperature". Crystallization depends on too many different factors such as the crystallization technique, solvent, solvent mixture, presence of seed crystals, temperature etc. Growth temperature is just one of these factors which can often hardly be reproduced. For some very useful guides to the various crystallization techniques please have a look at the attached articles.
Good luck with your work and please stay safe and healthy! With best wishes, Frank Edelmann
Yes, in general there is a temperature window within which a single polytype of the crystal is stable. Concept of Ellingham diagram can be taken in consideration for understanding this. Ellingham diagram shows the temperature dependence of the stability of compounds. One classical case is of of SiC single crystal (which is now known to exist in 200+ polytypes) can be studied using this reference: [20] W. F. Knippenberg, Philips Research Reports, 18 (1963) 161-274.
Dear Abduh Mohammad Abdulwahab P.S. In order to give you a helpful advice it would certainly be a good idea if you could specify which kind of compounds you are interested in. As I mentioned already in my previous answer, crystallization form solution (water or organic solvents) depends on very many factors, and crystallization temperatures here are often not reproducible. The situation os different when you crystallize a material like silicon carbide (SiC) from a melt as mentioned by Aman Arora. In that case there are normally well-defined temperatures or temperature ranges in which the material starts crystallizing.
I would like to endorse Frank T. Edelmann aforesaid answer. Here, the question is not well defined, thus it is essential to give specific material to be grown as the single crystal and to know the growth temperature effect. For illustration, for the semiconductor’s, the single crystals can be grown from their different melting point temperature.
Hello A. M. Abdulwahab,
Previous my answer for the single crystal growth, though the melting temperature is the specific parameter for single crystal growth. In addition, transcend of temperature parameter, there are various parameters which could annihilated the crystallization process (melt or solution). The single crystal growth is complex growth, to mention crystallization process of the binary and ternary materials from III-V and II-VI are subject to grow. More specifically, we have been grown the bulk single crystals growth of the Sb-based materials by applying Vertical Directional Solidification Process (VDS-Process). The Sb-based research analysis of the bulk single crystal (compound semiconductors) growth by VDS-Process is summarized here. Single crystals growth (VDS-Process) conclusions manifest that the growth is very much depends on valid other growth parameters too. Additionally some parameters, peculiarly prohibit the single crystal growth, are illustrated as: the purity of source materials, growth method applied, medium of growth inside crucible or ampoule, instrumental fluctuation (errors) during growth, thermo-dynamical condition, furnace temperature profile, single crystal growth cyclogram, the growth rotation rate of the growing crystal, the temperature gradient etc. However, we can’t disregard human handling of the end products.
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