Skip to main content
×
×
Home

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

  • Huifang Xu (a1), Zhizhang Shen (a1) and Hiromi Konishi (a1)
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.

Copyright
Corresponding author
*E-mail: hfxu@geology.wisc.edu
References
Hide All
Andresen, A.F. and Laar, B. (1970) The magnetic structure of Fe3Se4. Acta Chemica Scandinavica, 24, 24352439.
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.
Fleet, M.E. (1978) The pyrrhotite-marcasite transformation. The Canadian Mineralogist, 16, 3135.
Fleet, M.E. (1982) Synthetic smythite and monoclinic Fe3Se4. Physics and Chemistry of Minerals, 8, 241246.
Hawley, J.E. (1962) The Sudbury ores: their mineralogy and origin. The Canadian Mineralogist, 7, 1207.
Jellinek, F. (1957) The structures of the chromium sulphides. Acta Crystallographica, 10, 620628.
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.
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.
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.
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.
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.
Murowchick, J.B. and Barnes, H.L. (1986) Marcasite precipitation from hydrothermal solutions. Geochimica et Cosmochimica Acta, 50, 26152629.
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.
Pennycook, S. (2002) Structure determination through Z-contrast microscopy. Advances in Imaging and Electron Physics, 123, 173206.
Perdew, J.P., Burke, K. and Ernzerhof, M. (1996) Generalized gradient approximation made simple. Physical Review Letters, 18, 38653868.
Pierce, L.P. and Buseck, P.R. (1974) Electron imaging of pyrrhotite superstructures. Science, 186, 12091212.
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.
Skinner, B.J., Erd, R.C. and Grimaldi, F.S. (1964) Greigite, the thio-spinel of iron; a new mineral. American Mineralogist, 49, 543555.
Taylor, L.A. and Williams, K.L. (1972) Smythite, (Fe, Ni)9S11-a redefinition. American Mineralogist, 57, 15711577.
Tokonami, M., Nishiguchi, K. and Morimoto, N. (1972) Crystal structure of a monoclinic pyrrhotite (Fe7S8). American Mineralogist, 57, 10661080.
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.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Mineralogical Magazine
  • ISSN: 0026-461X
  • EISSN: 1471-8022
  • URL: /core/journals/mineralogical-magazine
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
×

Keywords

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed