This paper presents preliminary results of the structure model of a pure illite sam- ple from Hungary. The clay sample mined in the Tokaj region (Northern Hungary) is com- posed of predominating illite and minor smectite and quartz. Enrichment by sedimentation in water solvent of the illite fraction led to a nearly pure sample which was fully characterized using conventional microscopic and chemical analyses. Although, illite is a well known clay mineral used for many industrial applications (its crystallinity index is used to establish the degree of illitization in oil source rocks linked to oil generation) a structure model has never been refined to date. This is due to the fact that pure samples to be used for structure charac- terization are a rarity in nature and because the structure is affected by extensive planar dis- order. Thus, the structural characterization of this sample is of great importance for the un- derstanding of the structure of illite in general. The planar disorder prevents a simple struc- ture refinement using the Rietveld method and different algorithms must be used. Here, we present the results of structure simulations of powder patterns using NEWMOD, WILDFIRE and DIFFaX, which reveal the structure features and structure model of disorder. They are a good starting point for the combined structure/microstructure refinement which will be at- tempted using DIFFaX+

Model of structure disorder of illite: preliminary results

Leoni, Matteo
2006-01-01

Abstract

This paper presents preliminary results of the structure model of a pure illite sam- ple from Hungary. The clay sample mined in the Tokaj region (Northern Hungary) is com- posed of predominating illite and minor smectite and quartz. Enrichment by sedimentation in water solvent of the illite fraction led to a nearly pure sample which was fully characterized using conventional microscopic and chemical analyses. Although, illite is a well known clay mineral used for many industrial applications (its crystallinity index is used to establish the degree of illitization in oil source rocks linked to oil generation) a structure model has never been refined to date. This is due to the fact that pure samples to be used for structure charac- terization are a rarity in nature and because the structure is affected by extensive planar dis- order. Thus, the structural characterization of this sample is of great importance for the un- derstanding of the structure of illite in general. The planar disorder prevents a simple struc- ture refinement using the Rietveld method and different algorithms must be used. Here, we present the results of structure simulations of powder patterns using NEWMOD, WILDFIRE and DIFFaX, which reveal the structure features and structure model of disorder. They are a good starting point for the combined structure/microstructure refinement which will be at- tempted using DIFFaX+
2006
S., Ferrari; A. F., Gualtieri; G. H., Grathoff; Leoni, Matteo
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11572/82652
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