Abstract
Silicon-29 “magic angle spinning” nuclear magnetic resonance (NMR) spectroscopy has been used to study the changes in local Si environment during Al, Si ordering in synthetic cordierite, Mg2Al4Si5O18. In the most disordered form, crystallized from a glass, eight distinct tetrahedral sites for silicon can be identified and assigned, while there are only two distinguishable Si sites in the well-annealed ordered form. This allows the changes in the Si site environments to be determined as a function of annealing time for the transformation from the disordered to the ordered form. The first crystallized state has a considerable degree of partitioning between T1 and T2 sites with the following site occupancies: T1 − Al:Si=0.80:0.20, T2−Al:Si=0.27:0.73 The changes in Si environment are approximately linear with log time. The measured values of 29Si isotropic chemical shift do not fit well to previously determined correlations of shift with various structural parameters.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Andrew ER (1981) Magic angle spinning in solid state n.m.r. spectroscopy. Phil Trans Roy Soc London A299:505–520
Armbruster T, Bloss FD (1981) Mg-cordierite: Si/Al ordering, optical properties and distortion. Contrib Mineral Petrol 77:332–336
Brown ID, Shannon RD (1973) Empirical bond strength-bond length curves for oxides. Acta Crystallogr A29:266–282
Carpenter MA, Putnis A, Navrotsky A, McConnell JDC (1983) Enthalpy effects associated with Al/Si ordering in anhydrous Mg-cordierite. Geochim Cosmochim Acta 47:899–906
Cohen JP, Ross FK, Gibbs GV (1977) An X-ray and neutron diffraction study of hydrous low cordierite. Am Mineral 62:67–78
Engelhardt G, Lohse U, Lippmaa E, Tarmak M, Magi M (1981) 29Si-NMR-Untersuchungen zur Verteilung der Silicium und Aluminiumatome im Alumosilicatgitter von Zeolithen mit Faujasit-Struktur. Z Anorg Allg Chem 482:49–64
Fyfe CA, Gobbi GC, Hartman JS, Lenkinski RE, O'Brien JH, Beange ER, Smith MAR (1982) High resolution solid state MAS Spectra of 29Si, 27Al, 11B and other nuclei in inorganic systems using a narrow bore 400-MHz high resolution NMR spectrometer. J Magn Reson 47:168–174
Fyfe CA, Thomas JM, Klinowski J, Gobbi GC (1983) Magic angle spinning NMR spectroscopy and the structure of zeolites. Angew Chem 22:259–336
Gibbs GV (1966) The polymorphism of cordierite I: The crystal structure of low cordierite. Am Mineral 51:1068–1087
Klinowski J, Ramdas S, Thomas JM, Fyfe CA, Hartman JS (1982) A re-examination of Si,Al ordering in zeolites NaX and NaY. J Chem Soc Faraday Trans II 78:1025–1050
Lippmaa E, Magi M, Samosan A, Engelhardt G, Grimmer A-R (1980) Structural studies of silicates by solid state high resolution 29Si NMR. J Am Chem Soc 102:4889–4893
Lippmaa E, Magi M, Samosan A, Tarmak M, Engelhardt G (1981) Investigation of the structure of zeolites by solid state high resolution 29Si NMR. J Am Chem Soc 103:4992–4996
McMillan P, Putnis A, Carpenter MA (1984) A Raman spectroscopic study of Al/Si ordering in synthetic magnesium cordierite. Phys Chem Minerals. In press
Meagher EP, Gibbs GV (1977) The polymorphism of cordierite II: The crystal structure of indialite. Can Miner 15:43–49
Putnis A (1980) The distortion index in anhydrous Mg-cordierite. Contrib Mineral Petrol 74:135–141
Putnis A, Bish DL (1983) The mechanism and kinetics of Al,Si ordering in Mg cordierite. Am Mineral 68:60–65
Putnis A, Angel RJ (1985) Al,Si ordering in cordierite using “magic angle spinning” NMR. II. Models of Al,Si order from NMR data. Phys Chem Minerals 12:217–222
Ramdas S, Klinowski J (1984) A simple correlation between isotropic 29Si-NMR chemical shifts and T-O-T angles in zeolite frameworks. Nature 308:521–523
Schreyer W, Schairer JF (1961) Mg cordierites: a reinvestigation of the central part of the system MgO-Al2O3-SiO2. J. Petrol 2:324–406
Smart RM, Glasser FP (1977) Stable cordierite solid solutions in the MgO-Al2O3-SiO2 system: composition, polymorphism and thermal expansion. Science of Ceramics 9:256–263
Smith JV, Blackwell CS (1983) Nuclear magnetic resonance of silica polymorphs. Nature 303:223–225
Smith KA, Kirkpatrick RJ, Oldfield E, Henderson DM (1983) High resolution silica-29 nuclear magnetic resonance spectroscopic study of rock forming silicates. Am Mineral 68:1206–1215
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Putnis, A., Fyfe, C.A. & Gobbi, G.C. Al,Si ordering on cordierite using “magic angle spinning” NMR. Phys Chem Minerals 12, 211–216 (1985). https://doi.org/10.1007/BF00311290
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00311290