Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-24T08:22:40.763Z Has data issue: false hasContentIssue false

Mössbauer effect study on the mixed valence state of iron in tourmaline

Published online by Cambridge University Press:  05 July 2018

E. A. Ferrow
Affiliation:
Department of Mineralogy and Petrology, University of Lund, Sölvegatan 13, S-222 62 Lund, Sweden
H. Annersten
Affiliation:
Department of Mineralogy and Petrology, University of Uppsala, Box 555, S-751 22 Uppsala, Sweden
R. P. Gunawardane
Affiliation:
Department of Chemistry, University of Paradeniya, Paradeniya, Sri Lanka

Abstract

Mössbauer spectra of iron-bearing tourmaline, obtained at different temperatures, show the existence of thermally-activated charge delocalization among clusters of iron atoms situated in the Y and Z octahedra of the tourmaline structure. The temperature dependence indicates an unusually high activation energy for the delocalization process which suggests that the process takes place between crystallographically non-equivalent sites. Annealing of the tourmaline in hydrogen is observed to inhibit the delocalization process, thus localizing the electron into the Z-site.

Type
Mineralogy
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1988

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Amthauer, G. and Rossman, R.G. (1984) Mixed valence state of iron in minerals with cation cluster. Phys. Chem. Minerals 11, 37-51.CrossRefGoogle Scholar
Annersten, H., Ericsson, T. and Filippidis, A. (1982) Cation ordering in Ni-Fe olivines. Am. Mineral. 67, 1212-7.Google Scholar
Barton, R. Jr. (1969) Refinement of the crystal structure of buergerite and the absolute orientation of tourmaline. Acta Crystallogr. 25, 1523-33.Google Scholar
Burns, R.G. (1972) Mixed valencies and site occupancies of iron in silicate minerals from Mrssbauer spectroscopy. Can. J. Spectroscopy 17, 251-9.Google Scholar
Donnay, G. and Barton, R. Jr. (1972) Refinement of the crystal structure of elbaite and the mechanism of tourmaline solid solution. Tchermaks. Mineral. Petrpg. Mitt. 18, 273-86.Google Scholar
Donnay, G. and Barton, R. Jr. and Buerger, M.J. (1950) The determination of the crystal structure of tourmaline. Acta Crystallogr. 3, 379-88.CrossRefGoogle Scholar
Fortier, S. and Donnay, G. (1975) Schorl refinement showing composition dependence of the tourmaline structure. Can. Mineral. 13, 173-7.Google Scholar
Hermon, E., Simkin, D.J., Donnay, G. and Muir, W.B. (1973) The distribution of Fe2+ and Fe3+ in the iron-bearing tourmaline: A Mrssbauer study. Tchermaks Mineral. Petrog. Mitt. 19, 124-32.CrossRefGoogle Scholar
Iijima, S., Cowley, J.M. and Donnay, G. (1973) High resolution electron microscopy of tourmaline crystals. Ibid. 20,216-24.Google Scholar
Korovushkin, V.V., Kuzmin, V.I. andBelov, V.F. (1979) Mrssbauer studies of structural features in tourmaline of various genesis. Phys. Chem. Minerals 4, 209-20.CrossRefGoogle Scholar
Lotgering, F.K. and van Diepen, A.M. (1977) Electron exchange between z+ and Fe3+ on octahedral sites in spinels studied by means of paramagnetic and Mrssbauer spectra and susceptibility measurements. J. Phys. Chem. Solids 38, 565-72.CrossRefGoogle Scholar
Mattson, S.M. and Rossman, G.R. (1984) Ferric iron in tourmaline. Phys. Chem. Minerals 11, 225-34.CrossRefGoogle Scholar
Mattson, S.M. and Rossman, G.R. (1987) Fe2+-Fe3+ interaction in tourmaline. Ibid. 14,163-71.Google Scholar
Nolet, D.A. and Burns, R.G. (1979) A study of the temperature-dependent electron delocalization by the Mrssbauer Effect. Ibid. 4,221-34.Google Scholar
Saegusa, N., Price, D.C. and Smith, G. (1978) Analysis of the Mrssbauer spectra of several iron-rich tourmalines. International conference on the application of the MOssbauer effect. Kyoto, Japan.Google Scholar
Smith, G. (1978) A reassesment of the role of iron in the 5000-30 000 cm-1 region of the electron absorption of tourmaline. Phys. Chem. Minerals 3, 343-73.CrossRefGoogle Scholar