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Use of Rietveld Pattern Fitting to Determine the Weight Fraction of Crystalline Material in Natural Low Quartz Specimens

Published online by Cambridge University Press:  10 January 2013

Bernard Jordan
Affiliation:
Department of Chemical and Analytical Sciences, Deakin University, Geelong, Victoria 3217, Australia.
Brian H. O'Connor
Affiliation:
Department of Applied Physics, Curtin University of Technology, GPO Box U 1987, Perth, W.A. 6001, Australia.
Li Deyu
Affiliation:
Department of Applied Physics, Curtin University of Technology, GPO Box U 1987, Perth, W.A. 6001, Australia.

Abstract

Quantisation of low-quartz in crystalline mixtures has been performed by X-ray powder diffractometry (XRPD) for many years. Conventional methodology, using discrete-peak integrated intensities, is frequently performed employing calibrations prepared with natural low-quartz specimens. Previous research showed that from a conventional XRPD study of low-quartz specimens, the amorphous content of a suite of natural low-quartz specimens ranged from 1% to 28%. That study thereby underlined the importance in XRPD calibration of characterising the amorphous content (or its complementary quantity “weight fraction of crystalline material, WCFM” employed here). This paper describes an application of pattern-fitting Rietveld analysis for characterising the WCFM in a suite of low-quartz specimens. The results gave WCFM values ranging from 0.91 (esd, σ= 0.02) to 1.00(0.02) for six specimens for which the SiO2chemical content ≥ 99.5%.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1990

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