Clays and Clay Minerals

, Volume 41, Issue 3, pp 297–304 | Cite as

Rietveld Refinement and Fourier-Transform Infrared Spectroscopic Study of the Dickite Structure at Low Temperature

  • David L. Bish
  • Clifford T. Johnston


The full structure of dickite from St. Claire, Pennsylvania, including hydrogen atoms, was refined in space group Cc using time-of-flight neutron powder diffraction data obtained at 12 K and Rietveld refinement/difference-Fourier methods (Rwp = 2.62%, reduced χ2 = 1.915, 113 variables, a = 5.1474(6)Å, b = 8.9386(10)Å, c = 14.390(2)Å, and ß = 96.483(1)°). The non-hydrogen structure is essentially identical to published structures for dickite, but the hydrogen positions are distinct. The inner hydroxyl group is approximately parallel to the (001) plane, inclined by 1.3° towards the tetrahedral sheet. Contrary to published low-temperature infrared (IR) spectra, there is no evidence that dickite possess lower symmetry at low temperatures although there is tentative evidence for statistical occupancy of H3 on more than one site. Low-temperature IR spectra of St. Claire and Wisconsin dickites do not show evidence for more than four hydroxyl groups and are consistent with the reported structure. Upon cooling from 300 to 15 K, the position of the OH3 stretching band increased from 3710 to 3731 cm−1. This large, positive shift in frequency was attributed to the increase in the internuclear O-H3 ⋯ O distance upon cooling. The frequency of the 3655 cm−1 band initially decreased by 2 cm−1 to 3653 cm−1 upon cooling from 300–125 K; however, the band increased in frequency by 1 cm−1 upon further cooling to 15 K. This unusual change in frequency upon cooling is consistent with the assignment of this band to OH2 and OH4. The position of the OH1 stretching band decreased from 3622 to 3620 cm−1 upon cooling, which was attributed, in part, to the observed increase in the Al-O(H1)-Al angle at low temperature.

Key Words

Dickite FTIR Infrared spectroscopy Low temperature Neutron powder diffraction Rietveld refinement 


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  1. Adams, J. M. and Hewat, A. W. (1981) Hydrogen atom positions in dickite: Clays & Clay Minerals 29, 316–319.CrossRefGoogle Scholar
  2. Bellows, J. C. and Prasad, P. N. (1979) Dephasing times and linewidths of optical transitions in molecular crystals: Temperature dependence of line shapes, linewidths, and frequencies of Raman active phonons in naphthalene: J. Chem. Phys. 70, 1864–1871.CrossRefGoogle Scholar
  3. Bish, D.L. (1989) Rietveld refinement of the kaolinite structure at 88, 294, and 573K: in Program and Abstracts, 26th Annual Meeting of the Clay Minerals Society, Sacramento, California, p. 17.Google Scholar
  4. Bish, D. L., and Von Dreele, R. B. (1990) The crystal structure of kaolinite including hydrogen atoms: in Program and Abstracts, 27th Annual Meeting of the Clay Minerals Society, Columbia, Missouri, p. 25.Google Scholar
  5. Bookin, A. S., Drits, V. A., Plancon, A., and Tchoubar, C. (1989) Stacking faults in kaolin-group minerals in the light of real structural features: Clays & Clay Minerals 37, 297–307.CrossRefGoogle Scholar
  6. Brindley, G. W., Kao, C.-C., Harrison, J. L., Lipsicas, M, and Raythatha, R. (1986) Relation between structural disorder and other characteristics of kaolinites and dickites: Clays & Clay Minerals 34, 239–249.CrossRefGoogle Scholar
  7. Dollase, W. A. (1986) Correction of intensities for preferred orientation in powder diffractometry: Application of the March model: J. Appl. Crystallogr. 19, 267–272.CrossRefGoogle Scholar
  8. Farmer, V. C. (1974) The layer silicates: in The Infrared Spectra of Minerals, V. C. Farmer, ed., Mineralogical Society, London, 331–363.CrossRefGoogle Scholar
  9. Farmer, V. C. and Russell, J. D. (1964) The infra-red spectra of layer silicates: Spectrochimica Acta 20, 1149–1173.CrossRefGoogle Scholar
  10. Gruner, J. W. (1932) The crystal structure of dickite: Zeit. Krist. 83, 394–404.Google Scholar
  11. Johnston, C. T., Agnew, S. F., and Bish, D. L. (1990) Polarized single-crystal Fourier-transform infrared microscopy of Ouray dickite and Keokuk kaolinite: Clays & Clay Minerals 38, 373–583.CrossRefGoogle Scholar
  12. Joswig, W. and Drits, V. A. (1986) The orientation of the hydroxyl groups in dickite by X-ray diffraction: N. Jb. Miner. Mh., 19–22.Google Scholar
  13. Larson, A. C. and Von Dreele, R. B. (1988) Generalized structure analysis system: Los Alamos National Laboratory Rept. LAUR 86-748, 161 pp.Google Scholar
  14. Newnham, R. E. (1961) A refinement of the dickite structure and some remarks on polymorphism in kaolin minerals: Mineral. Mag. 32, 683–704.Google Scholar
  15. Newnham, R. E. and Brindley, G. W. (1956) The crystal structure of dickite: Acta Crystallogr. 9, 759–764.CrossRefGoogle Scholar
  16. Pauling, L. (1930) The structure of the chlorites: Proc. Natl. Acad. Sci, U.S.A. 16, 578–582.CrossRefGoogle Scholar
  17. Prost, R. (1984) Etude par spectroscopic infrarouge a basse temperature des groupes OH de structure de la kaolinite, de la dickite et de la nacrite: Agronomie 4, 403–406.CrossRefGoogle Scholar
  18. Prost, R., Dameme, A., Huard, E., and Driard, J. (1987) Infrared study of structural OH in kaolinite, dickite, and nacrite at 300 to 5 K: in Proc. Int. Clay Conf. Denver, 1985, L. G. Schultz, H. van Olphen, and F. A. Mumpton, eds., The Clay Minerals Society, Bloomington, Indiana, 17–23.Google Scholar
  19. Prost, R., Dameme, A., Huard, E., Driard, J., and Leydecker, J. P. (1989) Infrared study of structural OH in kaolinite, dickite, nacrite, and poorly crystalline kaolinite at 5 to 600 K: Clays & Clay Minerals 37, 464–468.CrossRefGoogle Scholar
  20. Rietveld, H. M. (1969) Profile refinement method for nuclear and magnetic structures: J. Appl. Crystallogr. 2, 65–71.CrossRefGoogle Scholar
  21. Rozhdestvenskaya, I. V., Bookin, A. S., Drits, V. A., and Finko, V. I. (1982) Proton positions and structural characteristics of dickite by X-ray diffraction: Miner. Zhur. 4, 52–58 (in Russian).Google Scholar
  22. Sen Gupta, P. K., Schlemper, E. O., Johns, W. D., and Ross, F. (1984) Hydrogen positions in dickite: Clays & Clay Minerals 32, 483–485.CrossRefGoogle Scholar
  23. Scott, H. G. (1983) The estimation of standard deviations in powder diffraction Rietveld refinements: J. Appl. Crystallogr. 16, 159–163.CrossRefGoogle Scholar
  24. Von Dreele, R. B., Jorgensen, J. D., and Windsor, C. G. (1982) Rietveld refinement with spallation neutron powder diffraction data: J. Appl. Crystallogr. 15, 581–589.CrossRefGoogle Scholar
  25. Wilson Jr., E. B., Decius, J. C., and Cross, P. C. (1955) Molecular Vibrations: The Theory of Infrared and Raman Vibrational Spectra: Dover Publications, New York, 388 pp.Google Scholar

Copyright information

© The Clay Minerals Society 1993

Authors and Affiliations

  • David L. Bish
    • 1
  • Clifford T. Johnston
    • 2
  1. 1.Earth and Environmental Sciences Division, Los Alamos National LaboratoryLos AlamosUSA
  2. 2.Department of Soil ScienceUniversity of FloridaGainesvilleUSA

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