Hostname: page-component-cd9895bd7-jkksz Total loading time: 0 Render date: 2024-12-29T12:08:03.788Z Has data issue: false hasContentIssue false

Natural occurrence of monoclinic Fe3S4 nano-precipitates in pyrrhotite from the Sudbury ore deposit: a Z-contrast imaging and density functional theory study

Published online by Cambridge University Press:  02 January 2018

Huifang Xu*
Affiliation:
NASA Astrobiology Institute, Department of Geoscience, University of Wisconsin-Madison, 1215 W Dayton Street, Madison, WI 53706, USA
Zhizhang Shen
Affiliation:
NASA Astrobiology Institute, Department of Geoscience, University of Wisconsin-Madison, 1215 W Dayton Street, Madison, WI 53706, USA
Hiromi Konishi
Affiliation:
NASA Astrobiology Institute, Department of Geoscience, University of Wisconsin-Madison, 1215 W Dayton Street, Madison, WI 53706, USA

Abstract

A monoclinic form of Fe3S4, a polymorph of cubic greigite, occurs as precipitates in a sample of pyrrhotite collected from the Sudbury ore deposit. The nano-crystal precipitates are in a topotaxial relationship with the host pyrrhotite-4C (Fe7S8). The precipitate and the host pyrrhotite have a coherent (001) interface. Half of the octahedral layers in the crystal structure are fully occupied by Fe, while the other half of the octahedral layers are occupied by Fe atoms and vacancies in an ordered manner along the a axis. The crystal structure of the Fe3S4 nano-precipitates has monoclinic symmetry with a space group of I2/m. Its c dimension is 6% smaller than that of the host pyrrhotite due to the large number of vacancies in the structure. Fractional coordinates for S and Fe atoms within the unit cell are determined from Z-contrast images and density functional theory (DFT). The calculated results match the measured values very well. It is proposed that the monoclinic Fe3S4 nano-precipitates formed through ordering of vacancies in pyrrhotite with a low Fe/S ratio (i.e. <0.875) at low temperature.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2015

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

Andresen, A.F. and Laar, B. (1970) The magnetic structure of Fe3Se4. Acta Chemica Scandinavica, 24, 24352439.CrossRefGoogle Scholar
Dudarev, S.L., Botton, G.A., Savrasov, S.Y., Humphreys, C.J. and Sutton, A.P. (1998) Electronenergy-loss spectra and the structural stability of nickel oxide: An LSDA+U study. Physical Review B, 57, 15051509.CrossRefGoogle Scholar
Fleet, M.E. (1978) The pyrrhotite-marcasite transformation. The Canadian Mineralogist, 16, 3135.Google Scholar
Fleet, M.E. (1982) Synthetic smythite and monoclinic Fe3Se4. Physics and Chemistry of Minerals, 8, 241246.CrossRefGoogle Scholar
Hawley, J.E. (1962) The Sudbury ores: their mineralogy and origin. The Canadian Mineralogist, 7, 1207.Google Scholar
Jellinek, F. (1957) The structures of the chromium sulphides. Acta Crystallographica, 10, 620628.CrossRefGoogle Scholar
Keays, R.R. and Lightfoot, P.C. (2004) Formation of Ni-Cu-Platinum Group Element sulfide mineralization in the Sudbury Impact Melt Sheet. Mineralogy and Petrology, 82, 217258.CrossRefGoogle Scholar
Kirkland, E.J. (1998) Advanced Computing in Electron Microscopy. Plenum Press, New York. Kresse, G. and Furthmüller, J. (1996) Efficiency of abinitio total energy calculations for metals and semiconductors using a plane-wave basis set. Computational Materials Science, 1, 1550.Google Scholar
Langenhorst, F., Harries, D. and Pollok, K. (2014) Nonstoichiometry, defects and superstructures in sulfide and oxide minerals. Pp. 261295. in: Minerals at the Nanoscale (F. Nieto and K.J.T. Livi, editors). EMU Notes in Mineralogy, 14. European Mineralogical Union, Eötvös University Press, Budapest.Google Scholar
Long, G., Zhang, H., Li, D., Sabirianov, R. and Zhang, Z. (2011) Magnetic anisotropy and coercivity of Fe3Se4 nanostructures. Applied Physics Letters, 99, 202-103.Google Scholar
Makovicky, E. (2006) Crystal structures of sulfides and other chalcogenides. Pp. 7125. in: Sulfide Mineralogy and Geochemistry (D.J. Vaughan, editor). Reviews in Mineralogy & Geochemistry, 61. Mineralogical Society of America and the Geochemical Society, Chantilly, Virginia, USA.Google Scholar
Murowchick, J.B. and Barnes, H.L. (1986) Marcasite precipitation from hydrothermal solutions. Geochimica et Cosmochimica Acta, 50, 26152629.CrossRefGoogle Scholar
Naldrett, A.J., Bray, J.G., Gasparrini, E.L., Podolsky, T. and Rucklidge, J.C. (1970) Cryptic variation and the petrology of the Sudbury Nickel Irruptive. Economic Geology, 65, 122155.CrossRefGoogle Scholar
Pennycook, S. (2002) Structure determination through Z-contrast microscopy. Advances in Imaging and Electron Physics, 123, 173206.CrossRefGoogle Scholar
Perdew, J.P., Burke, K. and Ernzerhof, M. (1996) Generalized gradient approximation made simple. Physical Review Letters, 18, 38653868.CrossRefGoogle Scholar
Pierce, L.P. and Buseck, P.R. (1974) Electron imaging of pyrrhotite superstructures. Science, 186, 12091212.CrossRefGoogle ScholarPubMed
Posfai, M. and Buseck, P.R. (1997) Modular structures in sulphides: sphalerite/wurtzite-, pyrite/marcasite-, and pyrrhotite-type minerals. Pp. 193235. in: Modular Aspects of Minerals (S. Merlino, editor). EMU Notes in Mineralogy, 1. European Mineralogical Union, Eötvös University Press, Budapest. Roldan, A., Santos-Carballal, D. and de Leeuw, N.H. (2013) A comparative DFT study of the mechanical and electronic properties of greigite Fe3S4 and magnetite Fe3O4. Journal of Chemical Physics, 138, 204712. Shi, F. (2013) Advanced Electron Microscopy of Novel Ferromagnetic Materials and Ferromagnet / Oxide Interfaces in Magnetic Tunnel Junctions. PhD Dissertation, University of Wisconsin-Madison, USA.Google Scholar
Skinner, B.J., Erd, R.C. and Grimaldi, F.S. (1964) Greigite, the thio-spinel of iron; a new mineral. American Mineralogist, 49, 543555.Google Scholar
Taylor, L.A. and Williams, K.L. (1972) Smythite, (Fe, Ni)9S11-a redefinition. American Mineralogist, 57, 15711577.Google Scholar
Tokonami, M., Nishiguchi, K. and Morimoto, N. (1972) Crystal structure of a monoclinic pyrrhotite (Fe7S8). American Mineralogist, 57, 10661080.Google Scholar
Xu, H., Shen, Z., Konishi, H., Fu, P. and Szlufarska, I. (2014) Crystal structures of laihunite and intermediate phases between laihunite-1M and fayalite: Z-contrast imaging and ab initio study. American Mineralogist, 99, 881889.CrossRefGoogle Scholar