nucleation


nucleation

* * *

      the initial process that occurs in the formation of a crystal from a solution, a liquid, or a vapour, in which a small number of ions, atoms, or molecules become arranged in a pattern characteristic of a crystalline solid, forming a site upon which additional particles are deposited as the crystal grows.

      Nucleation processes are classed as heterogeneous or homogeneous. In the former, the surface of some different substance, such as a dust particle or the wall of the container, acts as the centre upon which the first atoms, ions, or molecules of the crystal become properly oriented; in the latter, a few particles come into correct juxtaposition in the course of their random movement through the bulk of the medium. Heterogeneous nucleation is more common, but the homogeneous mechanism becomes more likely as the degree of supersaturation or supercooling increases. Substances differ widely in the likelihood that they will crystallize under conditions in which the crystalline state is the inherently stable one; glycerol is a well-known example of a compound prone to supercooling.

* * *


Universalium. 2010.

Look at other dictionaries:

  • nucléation — ● nucléation nom féminin Formation, dans un milieu de structure et de composition définies, de germes constituant des centres de développement d une nouvelle structure physique ou chimique. (La nucléation est dite homogène si les germes sont… …   Encyclopédie Universelle

  • Nucleation — Nucleation. См. Зарождение. (Источник: «Металлы и сплавы. Справочник.» Под редакцией Ю.П. Солнцева; НПО Профессионал , НПО Мир и семья ; Санкт Петербург, 2003 г.) …   Словарь металлургических терминов

  • nucleation — index centralization Burton s Legal Thesaurus. William C. Burton. 2006 …   Law dictionary

  • nucleation — (n.) 1861, noun of action from nucleate (v.), from L. nucleatus, pp. of nucleare, from nucleus (see NUCLEUS (Cf. nucleus)) …   Etymology dictionary

  • Nucleation — Not to be confused with Microtubule nucleation . Nucleation is the extremely localized budding of a distinct thermodynamic phase. Some examples of phases that may form via nucleation in liquids are gaseous bubbles, crystals or glassy regions.… …   Wikipedia

  • nucleation — ˌn(y)üklēˈāshən noun ( s) : the process of nucleating or clustering the nucleation of communities in villages and cities A.J.Bruwer as a. : the formation of nuclei (as in a supersaturated vapor or the free air) kept a continuous record …   Useful english dictionary

  • nucleation — A general term used in polymerization or assembly reactions where the first steps are energetically less favoured than the continuation of growth. Polymerization is much faster if a pre formed seed is used to nucleate growth. (eg. microtubule… …   Dictionary of molecular biology

  • Nucléation — La nucléation ( germination ) est le phénomène suivant lequel apparaissent les premiers germes cristallins d une phase solide ou d un composé, aussi appelé nuclei (groupe d atomes ou d ions présentant une structure ordonnée correspondant à la… …   Wikipédia en Français

  • nucleation — užuomazgų sudarymas statusas T sritis radioelektronika atitikmenys: angl. nucleation; nucleus formation vok. Keimbildung, f; Kernbildung, f rus. зародышеобразование, n; образование зародышей, n pranc. formation de germes, f; germination, f …   Radioelektronikos terminų žodynas

  • nucleation — užuomazgų susidarymas statusas T sritis fizika atitikmenys: angl. formation of nuclei; nucleation vok. Keimbildung, f; Kernbildung, f rus. образование зародышей, n pranc. formation des germes, f; germination, f …   Fizikos terminų žodynas


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.