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Mössbauer spectroscopy of phyllosilicates: effects of fitting models on recoil-free fractions and redox ratios

Published online by Cambridge University Press:  09 July 2018

M. D. Dyar*
Affiliation:
Department of Astronomy, Mount Holyoke College, 50 College Street, South Hadley, MA 01075, USA
M. W. Schaefer
Affiliation:
Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803, USA
E. C. Sklute
Affiliation:
Department of Astronomy, Mount Holyoke College, 50 College Street, South Hadley, MA 01075, USA
J. L. Bishop
Affiliation:
SETI Institute, 515 N. Whisman Road, Mountain View, CA 94043 USA
*

Abstract

Clay minerals are ubiquitous constituents in soils on Earth, are occasionally found in meteorites, and may also occur on planetary surfaces in the presence of water. However, little is known about the fundamental Mössbauer parameters (the intrinsic isomer shift, δI, the characteristic Mössbauer temperature, θM, and the recoil-free fraction, f) that are characteristic of clay minerals and critical to the correct interpretation of the Fe3+/ΣFe ratios as well as the mineral modes. Spectra of well characterized single mineral samples at multiple temperatures may be used for the determinations of f. Hence, measurements of five-layer silicates with a range of layer types are presented here: nontronite, Fe-smectite, glauconite, annite and biotite. The spectra were fitted using three different software packages: WMOSS from Science, Engineering & Education Co. in Minnesota; Recoil, from the University of Ottawa in Canada; and two programs used at the University of Ghent in Belgium. Four different approaches to modelling line shapes were used: (1) Lorentzian; (2) pseudo-Voigt (convolution of Lorentzian and Gaussian curves); (3) quadrupole-splitting distributions (QSD); and (4) a technique that does not assume a particular line shape (subsequently referred to as ‘model-independent’). Values of δI, θM and f were determined using the method of De Grave & Van Alboom (1991).

Results show that multiple doublets are routinely required by all models to represent Fe-site occupancy, even when all the Fe atoms of the same valence are in the same site, as is the case for dioctahedral smectite, nontronite, mica and glauconite. Consistent values of centre shift (δ) and quadrupole splitting (Δ) were obtained for the two distributions of M2Fe3+ in the smectites. In glauconite, a single Fe2+ doublet was clearly resolved and gave systematic values for δ, Δ and area, but the two Fe3+ doublets were less defined. In annite, two Fe2+ and two Fe3+ doublets were modelled, while three Fe2+ and one Fe3+ doublet were used for biotite. Three different programs that use Lorentzian line shapes gave very similar results for δ, Δ and area. The two different implementations of QSD line shapes gave similar but sometimes slightly different results, and the pseudo-Voigt and model-independent fits usually fell between the ranges for Lorentzian and QSD results.

The value of δI is ~0.58 mm/s for Fe3+ and ~1.31 mm/s for Fe2+ across all models and line shapes, which is expected because the Fe3+ has an additional shielding 3d electron. Values for θM data are nearly identical for Fe3+ in nontronite and Fe-smectite (~450 K), somewhat varied for Fe3+ in glauconite and biotite (θM = ~730 K and ~615 K, respectively), and relatively distinct for Fe2+ (~350 K). Some values for θM and f could not be determined due to the non-monotonic behaviour of the fitted values for δ as a function of temperature. Values of f295 were 0.821–0.917 for Fe3+ and 0.662–0.743 for Fe2+, consistent with previous studies of the recoil-free fraction in micas and other silicates. Calculated scatter in δ, Δ, area and f values as a function of different line shapes and computer software was significantly reduced at lower temperatures. Sources of error in each of the calculated parameters are discussed.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2008

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References

Bancroft, G.M. (1969) Quantitative site populations in silicate minerals by the Mössbauer effect. Chemical Geology, 5, 255258.CrossRefGoogle Scholar
Bancroft, G.M. & Brown, J.R. (1975) A Mössbauer study of coexisting hornblendes and biotites: quantitative Fe3+/Fe2+ ratios. American Mineralogist, 60, 265272.Google Scholar
Bishop, J.L., Murad, E., Madejová, J., Komadel, P., Wagner & Scheinost, A.C. (1999) Visible, Mössbauer and infrared spectroscopy of dioctahedral smectites: structural analyses of the Fe-bearing smectites Sampor, SWy-1 and SWa-1. Pp. 413419 in: Proceedings of the 11th International Clay Conference, 1997, Bahia, Argentina.Google Scholar
Bishop, J., Madejová, J., Komadel, P. & Fröschl, H. (2002a) The influence of structural Fe, Al and Mg on the infrared OH bands in spectra of dioctahedral smectites. Clay Minerals, 37, 607616.CrossRefGoogle Scholar
Bishop, J.L., Murad, E. & Dyar, M.D. (2002b) The influence of octahedral and tetrahedral cation substitution on the structure of smectites and serpentines as observed through infrared spectroscopy. Clay Minerals, 37, 617628.CrossRefGoogle Scholar
Bowen, L.H., De Grave, E., Reid, D.A., Graham, R.C. & Edinger, S.B. (1989) Mössbauer study of a California desert celadonite and its pedogenically-related smectite. Physics and Chemistry of Minerals, 16, 697703.CrossRefGoogle Scholar
Burns, R.G. & Solberg, T.C. (1990) Spectroscopic characterization of minerals and their surfaces. ACS Symposium series, 415, 262283.CrossRefGoogle Scholar
Čičel, B. & Komadel, P. (1994) Structural formulae of layer silicates. Pp. 114136 in: Quantitative Methods in Soil Mineralogy (Amonette, J.E. & Zelazny, L.W., editors). Soil Science Society of America, Madison, Wisconsin, USA.Google Scholar
Cooke, J.P. Jr. (1867) On cryophyllite, a new mineral species of the mica family, with some associated minerals in the granite of Rockport, Mass. American Journal of Science, 2n. Series, 43, 217230.Google Scholar
de Bakker, P. (1994) Grondige Mössbauerstudie van de selectief magnetisch verdunde spinel system MgFe2-xCrxO4 (0.0 = x = 2.0) en Mg1-xZnxFe1.5 Cr0.5O4 (0.0 = x = 1.0). PhD thesis. University of Ghent, Belgium.Google Scholar
De Grave, E. & Eeckhout, S.G. (2003) 57Fe Mossbauer effects studies of Ca-rich, Fe-bearing clinopyroxenes; Part III. Diopside. American Mineralogist, 88, 11451152.CrossRefGoogle Scholar
De Grave, E. & Van Alboom, A. (1991) Evaluation of ferrous and ferric Mössbauer fractions. Physics and Chemistry of Minerals, 18, 337342.CrossRefGoogle Scholar
De Grave, E., Verbeeck, A.E. & Chambaere, D.G. (1985) Influence of small aluminum substitutions on the hematite lattice. Physics Letters, A107, 181184.CrossRefGoogle Scholar
Drame, H. (2005) Cation exchange and pillaring of smectites by aqueous Fe nitrate solutions. Clays and Clay Minerals, 53, 335347.CrossRefGoogle Scholar
Dyar, M.D. (1984) Precision and interlaboratory reproducibility of measurements of the Mössbauer effect in minerals. American Mineralogist, 69, 11271144.Google Scholar
Dyar, M.D. (2002) Optical and Mössbauer spectroscopy of iron in micas. Pp. 313349 in: Advances in Micas (Mottana, A. & Sassi, F.). Reviews in Mineralogy and Geochemistry 46. Mineralogical Society of America and The Geochemical Society, Chantilly, Virginia, USA.CrossRefGoogle Scholar
Dyar, M.D. & Burns, R.G. (1986) Mössbauer spectral study of ferruginous one-layer trioctahedral micas. American Mineralogist, 71, 951961.Google Scholar
Dyar, M.D., Agresti, D.G., Schaefer, M., Grant, C.A. & Sklute, E.C. (2006) Mössbauer spectroscopy of earth and planetary materials. Annual Reviews of Earth and Planetary Science, 34, 83125.CrossRefGoogle Scholar
Eeckhout, S.G. & De Grave, E. (2003a) 27Fe Mossbauer effects studies of Ca-rich, Fe-bearing clinopyroxenes. Part, I. Paramagnetic spectra of magnesian hedenbergite. American Mineralogist, 88, 11291137.CrossRefGoogle Scholar
Eeckhout, S.G. & De Grave, E. (2003b) 57Fe Mossbauer effects studies of Ca-rich, Fe-bearing clinopyroxenes. Part II. Magnetic spectra of magnesian hedenbergite. American Mineralogist, 88, 11381144.CrossRefGoogle Scholar
Eeckhout, S.G. & De Grave, E. (2003c) Evaluation of ferrous and ferric Mössbauer fractions. Part II. Physics and Chemistry of Minerals, 30, 142146.CrossRefGoogle Scholar
Eeckhout, S.G., De Grave, E., McCammon, C.A. & Vochten, R. (2000) Temperature dependence of the hyperfine parameters of synthetic P21/c Mg-Fe clinopyroxenes along the MgSiO3-FeSiO3 join. American Mineralogist, 85, 943952.CrossRefGoogle Scholar
Ericsson, T., Wäppling, R. & Punakivi, K. (1977) Mössbauer spectroscopy applied to clay and related minerals. Geologiska Foreningens i Stockholm Forhandlingar, 99, 229244.CrossRefGoogle Scholar
Fialips, C.-I., Huo, D., Yan, L., Wu, J. & Stucki, J.W. (2002) Infrared study of reduced and reduced-reoxidized ferruginous smectite. Clays and Clay Minerals, 50, 455469.CrossRefGoogle Scholar
Foster, M.D. (1960) Interpretation of the composition of trioctahedral micas. US Geological Survey Professional Paper, B354, 68.Google Scholar
Frauenfelder, H. (1962) The Mössbauer Effect. W. A. Benjamin, New York.Google Scholar
Goldanskii, V.I. & Herber, R.H. (1968) Chemical Applications of Mössbauer Spectroscopy. Academic Press, New York, 701 pp.Google Scholar
Goodman, B.A., Russell, J.D., Fraser, A.R. & Woodhams, F.W.D. (1976) A Mössbauer and I.R. spectroscopic study of the structure of nontronite. Clays and Clay Minerals, 24, 5359.CrossRefGoogle Scholar
Govindaraju, K. (1979) Report (1968-1978) on two mica reference samples: biotite mica-Fe and phlogopite mica-Mg. Geostandards Newsletter, 3, 324.CrossRefGoogle Scholar
Govindaraju, K., Rubeska, I. & Paukert, T. (1994) 1994 report on zinnwaldite ZW-C analysed by ninety-two GIT-IWG member-laboratories. Geostandards Newsletter, 18, 142.CrossRefGoogle Scholar
Grant, C.A. (1995) Sources of experimental and analytical error in measurements of the Mössbauer effect in amphibole. PhD thesis, University of Oregon, USA.Google Scholar
Heller-Kallai, L. & Rozenson, I. (1981) The use of Mössbauer spectroscopy of iron in clay minerals. Physics and Chemistry of Minerals, 7, 223238.CrossRefGoogle Scholar
Herberle, J. (1971) The Debye integrals, the thermal shift and the Mössbauer fraction. Mössbauer Effect Methodology, 7, 299308.CrossRefGoogle Scholar
Kalinichenko, A.M., Litovchenko, A.S., Matyash, I.V., Pol’shin, E.V. & Ivaniskiy, V.P. (1973) Osobennosti kristallokhimii sloistykh silikatov po dannym radio-spektroskopy. Naukova Dumka, 108.Google Scholar
Karakassides, M.A., Gournis, D., Simopoulos, T. & Petridis, D. (2000) Mössbauer and infrared study of heat-treated nontronite. Clays and Clay Minerals, 48, 6874.CrossRefGoogle Scholar
Lafleur, L.D. & Goodman, C. (1971) Characteristic temperatures of the Mössbauer fraction and thermal-shift measurements in iron and iron salts. Physics Reviews, B4, 29152920. CrossRefGoogle Scholar
Lagarec, K. & Rancourt, D.G. (1971) Extended Voigtbased analytic line shape method for determining N-dimensional correlated hyperfine parameter distributions in Mössbauer spectroscopy. Nuclear Instruments and Methods in Physics Research, B129, 266280.Google Scholar
Lalonde, A.E., Rancourt, D.G. & Ping, J.Y. (1998) Accuracy of ferric/ferrous determinations in micas: a comparison of Mössbauer spectroscopy and the Pratt and Wilson wet-chemical methods. Hyperfine Interactions, 117, 175204.CrossRefGoogle Scholar
Li, Z., Ping, J.Y. & Liu, M.L. (2002) Distribution of Fe2+ and Fe3+ and next-nearest neighbour effects in natural chromites: comparison between results of QSD and Lorentzian doublet analysis. Physics and Chemistry of Minerals, 29, 485494.CrossRefGoogle Scholar
Long, G.J., Cranshaw, T.E. & Longworth, G. (1983) The ideal Mössbauer effect absorber thicknesses. Mössbauer Effect Reference Data Journal, 6, 4249.Google Scholar
Murad, E. (1998) Clays and clay minerals: what can Mössbauer spectroscopy do to help understand them. Hyperfine Interactions, 117, 3970.CrossRefGoogle Scholar
Murad, E. & Cashion, J.D. (2004) Mössbauer Spectroscopy of Environmental Materials and their Industrial Utilization. Kluwer Academic Publishers, Boston/Dordrecht.CrossRefGoogle Scholar
Novak, I. & Čičel, B. (1978) Dissolution of smectites in hydrochloric acid: II. Dissolution rate as a function of crystallochemical composition. Clays and Clay Minerals, 26, 341344.CrossRefGoogle Scholar
Ping, J.Y., Rancourt, D.G. & Stadnik, Z.M. (1991) Voigt-based methods for arbitrary shape quadrupole splitting distributions (QSD’s) applied to quasi-crystals. Hyperfine Interactions, 69, 493496.CrossRefGoogle Scholar
Pollak, H. & Stevens, J.G. (1986) Phyllosilicates: a Mössbauer evaluation. Hyperfine Interactions, 29, 11531156.CrossRefGoogle Scholar
Pollak, H., DeCoster, M. & Amelinckx, S. (1962) Mössbauer effect in biotite. Physica Status Solidi, 2, 1653-1659.Google Scholar
Rancourt, D.G. (1994a) Mössbauer spectroscopy of minerals I. Inadequacy of Lorentzian-line doublets in fitting spectra arising from quadrupole splitting distributions. Physics and Chemistry of Minerals, 21, 244249.CrossRefGoogle Scholar
Rancourt, D.G. (1994b) Mössbauer spectroscopy of minerals II. Problem of resolving cis and trans octahedral Fe + sites. Physics and Chemistry of Minerals, 21, 250257.CrossRefGoogle Scholar
Rancourt, D.G. (1998) Mössbauer spectroscopy in clay science. Hyperfine Interactions, 117, 338.CrossRefGoogle Scholar
Rancourt, D.G. & Ping, J.Y. (1991) Voigt-based methods for arbitrary-shape static hyperfine parameter distributions in Mössbauer spectroscopy. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 58, 8597.CrossRefGoogle Scholar
Rancourt, D.G. & Ping, J.Y. (1992) Thickness effects with intrinsically broad absorption lines. Hyperfine Interactions, 71, 14331436.Google Scholar
Rancourt, D.G., McDonald, A.M., Lalonde, A.E. & Ping, J.Y. (1993) Mössbauer absorber thickness for accurate site populations in Fe-bearing minerals. American Mineralogist, 78, 17.Google Scholar
Rancourt, D.G., Ping, J.Y. & Berman, R.G. (1994a) Mössbauer spectroscopy of minerals III. Octahedral-site Fe + quadrupole splitting distributions in the phlogopite-annite series. Physics and Chemistry of Minerals, 21, 258267.CrossRefGoogle Scholar
Rancourt, D.G., Christie, I.A.D., Royer, M., Kodama, H., Robert, J.L., Lalonde, A.E. & Murad, E. (1994b) Determination of accurate [4]Fe3+, [6]Fe3+, and [6]Fe2+ site populations in synthetic annite by Mössbauer spectroscopy. American Mineralogist, 79, 5162.Google Scholar
Rancourt, D.G., Ping, J.Y. & Robert, J.L. (1996) Octahedral site Fe2+ quadrupole splitting distributions from Mössbauer spectroscopy along the (OH, F) join. Physics and Chemistry of Minerals, 23, 6371.CrossRefGoogle Scholar
Redhammer, G.J. (1998) Characterisation of synthetic trioctahedral micas by Mössbauer spectroscopy. Hyperfine Interactions, 117, 85115.CrossRefGoogle Scholar
Royer, M. (1991) MSc thesis, 111 pp. University of Ottawa, Canada.Google Scholar
Skogby, H., Annersten, H., Domeneghetti, M.C., Molin, G.M. & Tazzoli, V. (1992) Iron distribution in orthopyroxene: a comparison of Mössbauer spectroscopy and X-ray refinement results. European Journal of Mineralogy, 4, 441452.CrossRefGoogle Scholar
Smith, A.E. (2005) New Hampshire mineral locality index. Rocks and Minerals, 80, 242261 CrossRefGoogle Scholar
Tennant, W.C. (1992) Analysis of single-crystal Mössbauer data in low symmetry 27Fe centres. Journal of Physics: Condensed Matter, 4, 6993-7008.Google Scholar
Tennant, W.C., Finch, J., Aldridge, L.P. & Gainsford, G.J. (1992) The electric field gradient and mean squared displacement tensor in 1M biotites investigated by Mössbauer spectroscopy. Journal of Physics: Condensed Matter, 4, 54475459.Google Scholar
Voigt, W. (1912) Uber das Gesetz der Intensitätsverteilung innerhalb der Linien eines Gasspektrums. Sitzungsberichte der mathematisch-physikalischen. Klasse der Königlich Bayerischen Akademie der Wissenschaften, 1912, 603620.Google Scholar
Whipple, E.R. (1968) Quantitative Mössbauer spectra and chemistry of iron. Earth and Atmospheric Science. Massachusetts Institute of Technology, Cambridge, Massachusetts, USA, 187 pp.Google Scholar
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