Abstract
The electric field gradient at the octahedral sites in biotite is calculated by use of the point charge model for the ideal crystal structure. The contribution from the overlap distortions of cation orbitals by the surrounding ligands is included. The calculated values of the ferric quadrupole splittings are in good agreement with those obtained from Mössbauer spectra of micas. The effect of the neighbouring point defects and of real structure features of biotite on the electric field gradient are computed. It has been found that various point defects in adjacent sites produce varying values of ferric quadrupole splittings, which exceed the difference between the ideal parameters at the two distinct octahedral sites. A new interpretation of the biotite Mössbauer spectra is suggested.
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References
Annersten, H.: Mössbauer studies of natural biotites. Am. Mineralogist 59, 143–151 (1974)
Bancroft, G.M.: Mössbauer spectroscopy — an introduction for inorganic chemists and geochemists. London: McGraw-Hill 1973, p. 186
Bancroft, G.M., Brown, J.R.: A Mössbauer study of coexisting hornblendes and biotites, quantitative Fe3+/Fe2+ ratios. Am. Mineralogist 60, 265–272 (1975)
Clementi, E.: Tables of atomic functions. Suppl. to IBM J. Res. Develop., 1, (1965)
Donnay, G., Morimoto, N., Takeda, H., Donnay, J.D.H.: Trioctahedral one-layer micas. 1. Crystal structure of a synthetic iron mica. Acta Cryst. 17, 1369–1373 (1964)
Forbes, Warren C.: An interpretation of the hydroxyl contents in biotites and muscovites. Mineral. Mag. 38, 712–720 (1972)
Goodman, B.A.: The Mössbauer spectrum of a ferrian muscovite and its implications in the assignment of sites in dioctahedral micas. Mineral. Mag. 40, 513–517 (1976)
Goodman, B.A., Wilson, M.J.: A study of the weathering of a biotite using the Mössbauer effect. Mineral. Mag. 39, 448–454 (1973)
Hafner, S.S., Raymond, M.: Effect of Oxygen Octupoles on the Electric-Field-Gradient at the Al3+ sites in Corundum (α-Al2O3), J. Chem. Phys. 52, 279–281 (1970)
Haggström, L., Wappling, R., Annersten, H.: Mössbauer study of iron-rich biotites. Chem. Phys. Lett. 4, 107–108 (1969)
Hogarth, D.D., Brown, F.F., Pritchard, A.M.: Biabsorption, Mössbauer spectra and chemical investigation of five phlogopite samples from Quebec. Can. Mineralogist 10, 710–722 (1970)
Hogg, C.S., Meads, R.E.: The Mössbauer spectra of several micas and related minerals. Mineral. Mag. 37, 606–614 (1970)
Hogg, C.S., Meads, R.E.: A Mössbauer study of thermal decomposition of biotites. Mineral. Mag. 40, 79–88 (1975)
Ingalls, R.: Electric-field gradient tensor in ferrous compounds. Phys. Rev. 133, A787-A795 (1964)
Krzanowsky, W.J., Newman, A.C.D.: Computer simulation of cation distribution in the octahedral layers of micas. Mineral. Mag. 38, 926–935 (1972)
Marfunin, A.S.: Spectroscopy, luminescence and radiation centers in minerals, Moscow: Nedra 1975. (In Russian)
Polshin, E.V., Matyash, I.V.: Distribution of ions Fe2+ and Mg in the biotite octahedral layer from data of Mössbauer spectra. Constitution and property of minerals. Vol. 7, pp. 51–54 Kiev: Naukova Dumka 1973. (In Russian)
Raymond, M., Hafner, S.S.: Nuclear Quadrupole Moment of 57mFe from α-Fe2O3 data. Phys. Rev. B 1, 979–981 (1970)
Rayner, J.H.: The crystal structure of phlogopite by neutron diffraction. Mineral. Mag. 39, 850–856 (1974)
Rothbauer, R.: Untersuchung eines 2M1-Muskovites mit Neutronenstrahlen. Neues Jahrb. Mineral. Mh, 137 (1967)
Sawatzky, G.A., Hupkes, J.: Redetermination of nuclear quadrupole moments from hyperfine interactions in compounds. Phys. Rev. Lett. 25, 100–101 (1970)
Sengupta, D., Artman, J.O., Sawatzky, G.A.: “Overlap” contributions to the electric-field-gradient components at the Fe3+ sites in FeOCl. Phys. Rev. B 4, 1484–1486 (1971)
Sharma, R.R.: Ferrous-ferric anomaly in quadrupole moment of Fe57m. Phys. Rev. Lett. 26, 563–565 (1971)
Sternheimer, R.M.: Quadrupole antishielding factors of ions. Phys. Rev. 130, 1423–1425 (1963)
Watson, R.E.: Analytic Hartree-Fock solutions for O2-. Phys. Rev. 111, 1108–1110 (1958)
Yassoglou, N.J., Nobeli, C., Kostikas, A.J., Simopoulos, A.C.: Weathering of mica flakes in two soils in Northern Greece evaluated by Mössbauer and conventional techniques. Soil Sci. Soc. Am. Proc. 36, 520–527 (1972)
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Mineeva, R.M. Relationship between mössbauer spectra and defect structure in biotites from electric field gradient calculations. Phys Chem Minerals 2, 267–277 (1978). https://doi.org/10.1007/BF00308178
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DOI: https://doi.org/10.1007/BF00308178