Nucléation et croissance cristalline dans les silicates liquides

Abstract : Microscopic mechanisms controling crystal nucieation and growth at temperatures below the solidus 1 but above Tg have been studied on glasses in the system CaO-AlzO3-SiOz. Experimental charges have been characterized over a wide range of length scaIes (SEM, TEM, Microprobe, DRX, raman spectroscopy). Minerais are enriched in Ca and have Si/Al approaching that of the parent liquid. A gradual change of Al/Si is observed with temperature. These results are explained by the relative mobilities of the different cations, of which Ca is several orders of magnitude faster than that of Si and Al.. The link between crystal growth and viscosity has been tested and explained by the common microscopic origine of these processes which is the breaking and formation of Si-O bonds. This link is broken when Al/Si of crystals and liquids are different, because the coupled diffusion of Al and Ca becomes the limiting factor of the crystal growth.
Document type :
Theses
File URL :
http://docnum.univ-lorraine.fr/prive/INPL_T_2004_ROSKOSZ_M.pdf
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https://hal.univ-lorraine.fr/tel-01750061
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Submitted on : Thursday, March 29, 2018 - 12:36:54 PM
Last modification on : Wednesday, July 25, 2018 - 9:59:40 AM

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  • HAL Id : tel-01750061, version 1

Citation

Mathieu Roskosz. Nucléation et croissance cristalline dans les silicates liquides. Sciences de la Terre. Institut National Polytechnique de Lorraine, 2004. Français. ⟨NNT : 2004INPL040N⟩. ⟨tel-01750061⟩

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