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Refined ettringite (Ca6Al2(SO4)3(OH)12∙26H2O) structure for quantitative X-ray diffraction analysis

  • F. Goetz-Neunhoeffer (a1) and J. Neubauer (a1)


A revised structure model of ettringite is presented, in order to provide quantitative X-ray diffraction (QXRD) of this mineral in cement pastes. The model is derived from two different existing structure models, both of which are suitable for restricted use but are inferior to the refined ettringite structure presented. In the first published ettringite structure proposed by Moore and Taylor [Acta Crystallogr. B 26, 386–393 (1970)], none of the 128 positions for H are given in the unit cell, which results in reduced scattering power for use of this model for quantification purposes. For the precise quantification of ettringite in samples together with anhydrous phases, the scattering factors of all atoms including the H positions are indispensable. The revised structure model is based on the data of Moore and Taylor, supplemented by the H positions determined by Berliner (Material Science of Concrete Special Volume, The Sydney Diamond Symposium, American Ceramic, Society, 1998, pp. 127–141) on the basis of a neutron diffraction structural investigation of deuterated ettringite at 20 K. Berliner’s (Material Science of Concrete Special Volume, The Sydney Diamond Symposium, American Ceramic Society, 1998, pp. 127–141) thermal parameter should not, however, be used, since a normal application is at room temperature. In order further to improve the structure model of ettringite, Rietveld refinement with the rigid body approach for OH and H2O molecules and SO4 tetrahedra was employed. The refined and improved ettringite structure model was tested for quantitative phase analysis by the determination of actual ettringite contents in mixtures with an internal standard. Synthesized and orientation-free prepared ettringite powders were investigated by X-ray powder diffraction analysis and quantified in four different blends with zircon. The quantification results with the new structure model demonstrate the superior quality of the revised ettringite structure.



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Adams, L. D. (1997). “Ettringite, the positive side,” 19th International Conference on Cement Microscopy, Cincinnati, OH, pp. 113.
Berliner, R. (1998). “The structure of ettringite,” Material Science of Concrete Special Volume, The Sidney Diamond Symposium, American Ceramic Society, pp. 127–141.
Carlson, E. T. and Berman, H. A. (1960). “Some observations on the calcium aluminate carbonate hydrates,” J. Res. Natl. Bur. Stand. JRNBAG 64A, 333341.
Dollase, W. A. (1986). “Correction of intensities for preferred orientation in powder diffractometry: application of the March Model,” J. Appl. Crystallogr. JACGAR 10.1107/S0021889886089458 19, 267272.
Dowty, E. (1999). “ATOMS”, Version 5.1.b Shape Software, 521 Hidden Valley Road, Kingsport, TN 37663, USA.
Finger, L. W. (1974). “Refinement of the crystal structure of zircon,” Carnegie Institution of Washington: Yearbook, Vol. 73, pp. 544547.
Goetz-Neunhoeffer, F. (2005). “Kinetics of the hydration of calcium aluminate cement with additives,” ZKG International ZKGIFW 58, 6572.
Goetz-Neunhoeffer, F., Neubauer, J., and Schwesig, P. (2005). “Mineralogical characteristics of Ettringites synthesized from solutions and suspensions,” Cem. Concr. Compos. CCOCEG (in Press, corrected proof, available online 17 May 2005).
ICDD (1989). “Powder diffraction file,” International Centre for Diffraction Data, edited by Frank McClune, 12 Campus Boulevard, Newtown Square, Pennsylvania, 19073-3272.
International Tables for Crystallography (2004). “Mathematical, physical and chemical tables,” Vol. C, 3rd ed., published for the International Union of Crystallography by Kluwer Academic Publishers, AA Dordrecht, The Netherlands.
Kern, A. A. and Coelho, A. A. (1998). “A new fundamental parameters approach in profile analysis of powder data,” in: Powder Diffraction, edited by Sen Gupta, S. P., (Allied Publishers Limited, Delhi), pp. 144151.81–7023–881–1
Michaelis, W. (1892). “Der Zementbazillus,” Tonindustrie-Zeitung , Berlin, 16, 105106.
Moore, A. E. and Taylor, H. F. W. (1970). “Crystal structure of ettringite,” Acta Crystallogr., Sect. B: Struct. Crystallogr. Cryst. Chem. ACBCAR 26, 386393.
Neubauer, J., Goetz-Neunhoeffer, F., Holland, U., and Schmitt, D. (2004). “In-situ XRD investigation of OPC Hydration,” Proceedings of the 26th International Conference on Cement Microscopy, San Antonio TX, pp. 124138.
Renaudin, G., Francois, M., and Evrard, O. (1999a). “Order and disorder in the lamellar hydrated tetracalcium monocarboaluminate compound,” Cem. Concr. Res. CCOCEG 29, 6369.
Renaudin, G., Kubel, F., Rivera, J. -P., and Francois, M. (1999b). “Structural phase transition and high temperature phase structure of Friedels salt,” Cem. Concr. Res. CCOCEG 29, 19371942.


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Refined ettringite (Ca6Al2(SO4)3(OH)12∙26H2O) structure for quantitative X-ray diffraction analysis

  • F. Goetz-Neunhoeffer (a1) and J. Neubauer (a1)


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