Abstract
Fe L2,3-edge XAS and XMCD studies have been used to unravel structural trends in the MgAl2O4–Fe3O4 solid solution where thermodynamic modeling has presented a challenge due to the complex ordering arrangements of the end-members. Partitioning of Fe3+ and Fe2+ between tetrahedral (Td) and octahedral (Oh) sites has been established. In the most Fe-rich samples, despite rapid quenching from a disordered state,
Unit-cell edges calculated from the spectroscopy-derived site occupancies show excellent agreement with those measured by X-ray powder diffraction on the bulk samples. Calculated saturation magnetic moments (Ms) for the Fe-rich samples also show excellent agreement with measured values but for the most Mg-rich samples are displaced to slightly higher values; this displacement is due to the presence of abundant Mg and Al disrupting the anti-parallel alignment of electron spins for Fe atoms.
Special collection papers can be found online at http://www.minsocam.org/MSA/AmMin/special-collections.html.
Acknowledgments
We thank Richard Pattrick and Vicky Coker for help in collecting XMCD on these samples at the Daresbury SRS and subsequently at the Advanced Light Source (ALS), Berkeley. The ALS is supported by the Director, Office of Science, Office of Basic Energy Sciences (OBES) of the U.S. Department of Energy (DOE) under Contract No. DE-AC02-05CH11231, and we thank Elke Arenholz for her assistance. R.J.H. acknowledges funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007–2013)/ERC Grant Agreement No. 320750. KMR gratefully acknowledges support from the DOE OBES Chemical Sciences, Geosciences, and Biosciences Division, through the Geosciences Program at Pacific Northwest National Laboratory. We also thank Gerrit van der Laan and Nick Telling for help with XMCD data analysis; David Plant carried out the electron microprobe analyses at Manchester and Paul Schofield provided information on the natural magnesian spinel. We also thank two anonymous referees for constructive comments.
References cited
Andreozzi, G.B., and Lucchesi, S.G. (2002) Intersite distribution of Fe2+ and Mg in spinel (sensu strico)—hercynite series by single-crystal X-ray diffraction. American Mineralogist, 87, 1113–1120.10.2138/am-2002-8-908Search in Google Scholar
Arenholz, E., and Prestemon, S.O. (2005) Design and performance of an eight-pole resistive magnet for soft X-ray magnetic dichroism measurements. Review Scientific Instruments, 76, 083908.10.1063/1.2008027Search in Google Scholar
Bahgat, A.A., Fayek, M.K., Hamalaway, A.A., and Eissa, N.A. (1980) The influence of substitution of iron ions on the electron hopping in magnetite. Journal of Physics C: Solid State Physics, 13, 2601–2608.10.1088/0022-3719/13/13/015Search in Google Scholar
Becker, K.D. (2001) In situ spectroscopy in solid state chemistry. Solid State Ionics, 141-142, 21–30.10.1016/S0167-2738(01)00716-0Search in Google Scholar
Berry, A.J., O’Neill, H.St.C., Javasuriya, K.D., Campbell, S.J., and Foran, G.J. (2003) XANES calibrations for the oxidation state of iron in a silicate glass. American Mineralogist, 88, 967–977.10.2138/am-2003-0704Search in Google Scholar
Binsted, N. (1998) Daresbury Laboratory EXCURV98 Program.Search in Google Scholar
Bowles, J.F.W., Howie, R.A., Vaughan, D.J., and Zussman, J. (2011) Rock Forming Minerals, vol 5A: Non-silicates: Oxides, Hydroxides and Sulphides. The Geological Society, London, 920pp.Search in Google Scholar
Brown, G.E. Jr., Calas, G., Waychunas, G.A., and Petiau, J. (1995) X-ray absorption spectroscopy and its applications in mineralogy and geochemistry. Reviews in Mineralogy, 18, 431–512.10.1515/9781501508974-013Search in Google Scholar
Byrne, J.M., Coker, V.S., Moise, S., Wincott, P.L., Vaughan, D.J., Tuna, F., Arenholz, E., van der Laan, G., Pattrick, R.A.D., Lloyd, J.R., and Telling, N.D. (2013) Controlled cobalt doping in biogenic magnetite nanoparticles. Journal Royal Society Interface, 10, 20130134.10.1098/rsif.2013.0134Search in Google Scholar PubMed PubMed Central
Carbonin, S., Russo, U., and Della Giusta, A. (1996) Cation distribution in some natural spinels from X-ray diffraction and Mössbauer spectroscopy. Mineralogical Magazine, 60, 355–368.10.1180/minmag.1996.060.399.10Search in Google Scholar
Cressey, G., Henderson, C.M.B., and van der Laan, G. (1993) Use of L-edge X-ray absorption spectroscopy to characterize multiple valence states of 3d transition metals; a new probe for mineralogical and geochemical research. Physics and Chemistry of Minerals, 20, 111–119.10.1007/BF00207204Search in Google Scholar
Della Giusta, A., Carbonin, S., and Ottonello, G. (1996) Temperature-dependent disorder in a natural Mg-Al-Fe2+-Fe3+–spinel. Mineralogical Magazine, 60, 603–616.10.1180/minmag.1996.060.401.06Search in Google Scholar
Dieckmann, R., and Schmalzried, H. (1977a) Defects and cation diffusion in magnetite (I). Berichte der Bunsen Gesellschaft, 81, 344–347.10.1002/bbpc.19770810320Search in Google Scholar
Dieckmann, R., and Schmalzried, H. (1977b) Defects and cation diffusion in magnetite (II). Berichte der Bunsen Gesellschaft, 81, 414–419.10.1002/bbpc.19770810412Search in Google Scholar
Dieckmann, R., Witt, C.A., and Mason, T. (1983) Defects and cation diffusion in magnetite (V): Electrical conduction, cation distribution and point defects in Fe3–dO4. Berichte der Bunsengesselschaft für physikalische Chemie, 87, 495–503.10.1002/bbpc.19830870609Search in Google Scholar
Doriguetto, A.C., Fernandes, N.G., Persiano, A.I.C., Filho, E.N., Grenèche, J.M., and Fabris, J.D. (2003) Characterization of a natural magnetite. Physics and Chemistry of Minerals, 30, 249–255.10.1007/s00269-003-0310-xSearch in Google Scholar
Droop, G.T.R. (1987) A general equation for estimating Fe3+ concentrations in ferro-magnesian silicates and oxides from microprobe analyses, using stoichiometric criteria. Mineralogical Magazine, 51, 431–435.10.1180/minmag.1987.051.361.10Search in Google Scholar
Eisenberger, P., and Brown, G.S. (1979) The study of disordered systems by EXAFS: Limitations. Solid State Communications, 29, 481–484.10.1016/0038-1098(79)90790-7Search in Google Scholar
Fleet, M.E. (1981) The structure of magnetite. Acta Crystallographica, B37, 917–920.10.1107/S0567740881004597Search in Google Scholar
Fleet, M.E. (1982) The structure of magnetite; defect structure II. Acta Crystallographica, B38, 1718–1723.10.1107/S056774088200702XSearch in Google Scholar
Gilbert, B., Katz, J.E., Denlinger, J.D., Yin, Y., Falcone, R., and Waychunas, G.A. (2010) Soft X-ray spectroscopy study of the electronic structure of oxidized and partially oxidised magnetite nanoparticles. Journal of Physical Chemistry, 114, 21994–22001.Search in Google Scholar
Goering, E., Gold, S., Lafkioti, M., and Schütz, G. (2006) Vanishing Fe 3d orbital moments in single-crystalline magnetite. Europhysics Letters, 73, 97–103.10.1209/epl/i2005-10359-8Search in Google Scholar
Goodenough, J.B., and Loeb, A.L. (1955) Theory of ionic ordering, crystal distortion, and magnetic exchange due to covalent forces in spinels. Physical Review, 98, 391–408.10.1103/PhysRev.98.391Search in Google Scholar
Gota, S., Gautier-Soyer, M., and Sacchi, M. (2000) Fe 2p absorption in magnetic oxides: Quantifying angular-dependent saturation effects. Physical Review B, 62, 4187–4190.10.1103/PhysRevB.62.4187Search in Google Scholar
Graf, C., Goroncy, C., Stumpf, P., Weschke, E., Boeglin, C., Ronneburg, H., and Rȕhl, E. (2015) Local magnetic and electronic structure of the surface region of postsynthetic oxidized iron oxide nanoparticles for magnetic resonance imaging. Journal of Physical Chemistry, 119, 19404–19414.Search in Google Scholar
Gunjakar, J.L., More, A.M., Gurav, C.D., and Lokhande, C.D. (2008) Chemical synthesis of spinel nickel ferrite (NiFe2O4) nano-sheets. Applied Surface Science, 254, 5844–5848.10.1016/j.apsusc.2008.03.065Search in Google Scholar
Gurman, S.J., Binsted, N., and Ross, I. (1984) A rapid, exact, curved-wave theory for EXAFS calculations. Journal Physics C, 17, 143–151.10.1088/0022-3719/17/1/019Search in Google Scholar
Harrison, R.J. (1997) Magnetic properties of the magnetite-spinel solid solution: Curie temperatures, magnetic susceptibilities and cation ordering. Ph.D. thesis, University of Cambridge, U.K.Search in Google Scholar
Harrison, R.J., and Putnis, A. (1995) Magnetic properties of the magnetite-spinel solid solution: Saturation magnetization and cation distributions. American Mineralogist, 80, 213–221.10.2138/am-1995-3-402Search in Google Scholar
Harrison, R.J., and Putnis, A. (1996) Magnetic properties of the magnetite-spinel solid solution: Curie temperatures, magnetic susceptibilities, and cation ordering. American Mineralogist, 81, 375–384.10.2138/am-1996-3-412Search in Google Scholar
Harrison, R.J., and Putnis, A. (1997a) Interaction between exsolution microstructures and magnetic properties of the magnetite-spinel solid solution. American Mineralogist, 82, 131–142.10.2138/am-1997-1-215Search in Google Scholar
Harrison, R.J., and Putnis, A. (1997b) The coupling between magnetic and cation ordering: a macroscopic approach. European Journal of Mineralogy, 9, 1115–1130.10.1127/ejm/9/6/1115Search in Google Scholar
Harrison, R.J., and Putnis, A. (1999) The magnetic properties and crystal chemistry of oxide spinel solid solutions. Surveys in Geophysics, 19, 461–520.10.1023/A:1006535023784Search in Google Scholar
Harrison, R.J., Redfern, S.A.T., and O’Neill, H.St.C. (1998) The temperature dependence of the cation distribution in synthetic hercynite (FeAl2O4) from in-situ neutron refinements. American Mineralogist, 83, 1092–1099.10.2138/am-1998-9-1018Search in Google Scholar
Harrison, R.J., Dove, M.T., Knight, K.S., and Putnis, A. (1999) In-situ diffraction study of non-convergent cation ordering in the (Fe3O4)1–x(MgAl2O4)x spinel solid solution. American Mineralogist, 84, 555–563.10.2138/am-1999-0409Search in Google Scholar
Henderson, C.M.B., Knight, K.S., Redfern, S.A.T., and Wood, B.J. (1996) High-temperature studies of octahedral cation exchange in olivine by neutron powder diffraction. Science, 271, 1713–1715.10.1126/science.271.5256.1713Search in Google Scholar
Henderson, C.M.B., Charnock, J.M., and Plant, D.A. (2007) Cation occupancies in Mg, Co, Ni, Zn, Al ferrite spinels: A multi-element study. Journal of Physics: Condensed Matter, 19, 1–25.10.1088/0953-8984/19/7/076214Search in Google Scholar
Hill, R.J., Craig, J.R., and Gibbs, G.V. (1979) Systematics of the spinel structure type. Physics and Chemistry of Minerals, 4, 317–349.10.1007/BF00307535Search in Google Scholar
Holland, T.J.B., and Redfern, S.A.T. (1997) Unit-cell refinement from powder diffraction data: the use of regression diagnostics. Mineralogical Magazine, 61, 65–77.10.1180/minmag.1997.061.404.07Search in Google Scholar
Huberty, J.M., Konishi, H., Heck, P.R., Fournelle, J.H., Valley, J.W., and Xu, H. (2012) Silician magnetite from the Dales Gorge Member of the Brockamn Iron Formation, Hamersley Group, Western Australia. American Mineralogist, 97, 26–37.10.2138/am.2012.3864Search in Google Scholar
Ildefonse, Ph., Coala, G., Flank, A.M., and Lagarde, P. (1995) Low Z elements (Mg, Al, and Si) K-edge absorption spectroscopy in minerals and disordered systems. Nuclear Instruments Methods Physics, B, 97, 172–175.10.1016/0168-583X(94)00710-1Search in Google Scholar
Kuiper, P., Searle, B.G., Duda, L.-C., Wolf, R.M., and van der Zaag, P.J. (1997) Fe L2,3 linear and circular dichroism of Fe3O4. Journal of Electron Spectroscopy and Related Phenomena, 86, 107–113.10.1016/S0368-2048(97)00053-4Search in Google Scholar
Lavina, B., Salviulo, G., and Della Giusta, A. (2002) Cation distribution and structure modelling of spinel solid solutions. Physics and Chemistry of Minerals, 29, 10–18.10.1007/s002690100198Search in Google Scholar
Lenglet, M. (2004) Iono-covalent character of the metal–oxygen bonds in oxides: a comparison of experimental and theoretical data. Active and Passive Electronic Components, 27, 1–60.10.1080/0882751031000116142Search in Google Scholar
Li, D., Peng, M., and Murata, T. (1999) Coordination and local structure of magnesium in silicate minerals and glasses: Mg K-edge XANES study. Canadian Mineralogist, 37, 199–206.Search in Google Scholar
Lilova, K.I., Xu, F., Rosso, K.M., Pearce, C.I., Kamali, S., and Navrotsky, A. (2012) Oxide solution calorimetry of Fe3+-bearing oxides and application to the magnetite-maghemite (Fe3O4-Fe8/3O4) system. American Mineralogist, 97, 164–175.10.2138/am.2012.3883Search in Google Scholar
Lindsley, D.H. (1976) The crystal chemistry and structure of oxide minerals as exemplified by the Fe-Ti oxides. Oxide Minerals, Mineralogical Society of America Short Course Notes, 3, L1–60.10.1515/9781501508561-006Search in Google Scholar
Liu, C., Zou, B., Rondinone, A.J., and Zhang, J. (2000) Chemical control of superparamagnetic properties of magnesium and cobalt spinel ferrite nanoparticles through atomic level magnetic couplings. Journal American Chemical Society, 122, 6263–6267.10.1021/ja000784gSearch in Google Scholar
Marco, J.F., Gancedo, R., Gracia, M., Gautier, J.L., Rios, E.I., Palmer, H.M., Greaves, C., and Berry, F.J. (2001) Cation distribution and magnetic structure of the ferrimagnetic spinel NiCo2O4. Journal of Materials Chemistry, 11, 3087–3093.10.1039/b103135jSearch in Google Scholar
Marshall, C.P., and Dollase, W.A. (1984) Cation arrangement in iron-zinc-chromium spinel oxides. American Mineralogist, 69, 928–936.Search in Google Scholar
Martignago, F., Andreozzi, G.B., and Dal Negro, A. (2006) Thermodynamics and kinetics of cation ordering in natural and synthetic Mg(Al,Fe3+)2O4 spinels from in situ high-temperature X ray diffraction. American Mineralogist, 91, 306–312.10.2138/am.2006.1880Search in Google Scholar
Mattioli, G.S., and Wood, B.J. (1988) Magnetite activities across the MgAl2O4–Fe3O4 spinel join with application to the thermobarometric estimates of upper mantle oxygen fugacity. Contributions to Mineralogy and Petrology, 98, 148–162.10.1007/BF00402108Search in Google Scholar
Nakajima, R., Stöhr, J., and Idzerda, Y.U. (1999) Electron-yield saturation effects in L-edge X-ray magnetic circular dichroism spectra of Fe, Co and Ni. Physical Review B, 59, 6421–6429.10.1103/PhysRevB.59.6421Search in Google Scholar
Nakatsuka, A., Ueno, H., Nakayama, N., Mizota, T., and Maekawa, H. (2004) Single-crystal X-ray diffraction study of cation distribution in MgAl2O4-MgFe2O4 spinel solid solution. Physics and Chemistry of Minerals, 31, 278–287.10.1007/s00269-004-0385-zSearch in Google Scholar
Navrotsky, A., and Kleppa, O.J. (1968) Thermodynamics of formation of simple spinels. Journal of Inorganic and Nuclear Chemistry, 30, 479–498.10.1016/0022-1902(68)80475-0Search in Google Scholar
Néel, L. (1955) Some aspects of rock magnetism. Advances in Physics, 4, 191–243.10.1080/00018735500101204Search in Google Scholar
Nell, J., and Wood, B.J. (1989) High-temperature cation distributions in Fe3O4-MgAl2O4-MgFe2O4-FeAl2O4 spinels from thermopower and conductivity measurements. American Mineralogist, 74, 339–351.Search in Google Scholar
Nell, J., Wood, B.J., and Mason, T.O. (1989) Thermodynamic properties in a multicomponent solid solution involving cation disorder: Fe3O4–MgAl2O4–MgFe2O4–FeAl2O4. American Mineralogist, 74, 1000–1015.Search in Google Scholar
O’Neill, H.St.C., and Navrotsky, A. (1983) Simple spinels: crystallographic parameters, cation radii, lattice energies, and cation distribution. American Mineralogist, 68, 181–194.Search in Google Scholar
O’Neill, H.St.C., (1984) Cation distributions and thermodynamic properties of binary spinel solid solutions. American Mineralogist, 69, 733–753.Search in Google Scholar
O’Neill, H.St.C., Annersten, H., and Virgo, D. (1992) The temperature dependence of the cation distribution in magnesioferrite (MgFe2O4) from powder XRD structural refinements and Mössbauer spectroscopy. American Mineralogist, 77, 725–740.Search in Google Scholar
Palin, E.J., and Harrison, R.J. (2007) A computational investigation of cation ordering phenomena in the binary spinel system MgAl2O4–FeAl2O4. Mineralogical Magazine, 71, 611–624.10.1180/minmag.2007.071.6.611Search in Google Scholar
Parker, R., and Tinsley, C.J. (1976) Electrical conduction in magnetite. Physica Status Solidi a, 88, 189–194.10.1002/pssa.2210330119Search in Google Scholar
Pattrick, R.A.D., van der Laan, G., Henderson, C.M.B., Kuiper, P., Dudzik, E., and Vaughan, D.J. (2002) Cation site occupancy in spinel ferrites studied by X ray magnetic circular dichroism: Developing a method for mineralogists. European Journal of Mineralogy, 14, 1095–1102.10.1127/0935-1221/2002/0014-1095Search in Google Scholar
Pearce, C.I., Henderson, C.M.B., Pattrick, R.A.D., van der Laan, G., and Vaughan, D.J. (2006) Direct determination of cation site occupancies in natural ferrite spinels by L2,3 X ray absorption spectroscopy and X ray magnetic circular dichroism. American Mineralogist, 91, 880–893.10.2138/am.2006.2048Search in Google Scholar
Pearce, C.I., Henderson, C.M.B., Telling, N.D., Pattrick, R.A.D., Charnock, J.M., Coker, V.S., Arenholz, E., Tuna, F., and van der Laan, G. (2010) Fe site occupancy in magnetite–ulvöspinel solid solutions: A new approach using X-ray magnetic circular dichroism. American Mineralogist, 95, 425–430.10.2138/am.2010.3343Search in Google Scholar
Pearce, C.I., Qafoku, O., Liu, J., Arenholz, E., Heald, S.M., Kukkadapu, R.K., Gorski, C.A., Henderson, C.M.B., and Rosso, K.M. (2012) Synthesis and properties of titanomagnetite (Fe3–xTixO4) nanoparticles: A tunable solid-state Fe(II/III) redox system. Journal of Colloid Interface Science, 387, 24–38.10.1016/j.jcis.2012.06.092Search in Google Scholar
Pellegrin, E., Hagelstein, M., Doyle, S., Moser, H.O., Fuchs, J., Vollath, D., Schuppler, S., James, M.A., Saxena, S.S., Nielsen, L., Rogajanu, O., Sawatzky, G.A., Ferrero, C., Borowski, M., Tjernberg, O., and Brookes, N. (1999) Characterization of nanocrystalline g-Fe3O4 with synchrotron radiation techniques. Physica Status Solidi b, 215, 797–801.10.1002/(SICI)1521-3951(199909)215:1<797::AID-PSSB797>3.0.CO;2-DSearch in Google Scholar
Peng, G., van Elp, J., Que, L. Jr., Armstrong, W.H., and Cramer, S.P. (1995) L-edge X-ray absorption and X-ray magnetic circular dichroism of oxygen-bridged dinuclear iron complexes. Journal American Chemical Society, 117, 2515–2519.10.1021/ja00114a014Search in Google Scholar
Redfern, S.A.T., Harrison, R.J., O’Neill, H.St.C., and Wood, D.R.R. (1999) Thermodynamics and kinetics of cation ordering in MgAl2O4 spinel up to 1600 °C from in situ neutron diffraction. American Mineralogist, 84, 299–310.10.2138/am-1999-0313Search in Google Scholar
Schedin, F., Hill, E.W., van der Laan, G., and Thornton, G. (2004) magnetic properties of stoichiometric and nonstoichiometric ultrathin Fe3O4(111) films on Al2O3(0001). Journal of Applied Physics, 96, 1165–1169.10.1063/1.1762715Search in Google Scholar
Shannon, R.D. (1976) Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallographica, A32, 751–767.10.1107/S0567739476001551Search in Google Scholar
Tiano, A.L., Papaefthymiou, G.C., Lewis, C.S., Han, J., Zhang, C., Li, Q., Shi, C., Abeykoon, A.M.M., Billinge, S.J.L., Stach, E., Thomas, J., Guerro, K., Munayco, J., Scorzelli, R.B., Burnham, P., Viescas, A.J., and Wong, S.S. (2015) Correlating size and composition-dependent effects with magnetic, Mössbauer, and pair distribution function measurements in a family of catalytically active ferrite nanoparticles. Chemistry of Materials, 27, 3572–3592.10.1021/acs.chemmater.5b00767Search in Google Scholar
Trcera, N., Cabaret, D., Rossano, S., Farges, F., Flank, An.-M., and Lagarde, P. (2009) Mg K-edge XANES spectra in crystals and oxide glasses: Experimental vs. theoretical approaches. Physics and Chemistry of Minerals, 36, 241–257.10.1007/s00269-008-0273-zSearch in Google Scholar
Uchida, H., Lavina, B., Downs, R.T., and Chesley, J. (2005) Single-crystal X ray diffraction of spinels from the San Carlos Volcanic Field, Arizona: Spinel as a geothermometer. American Mineralogist, 90, 1900–1908.10.2138/am.2005.1795Search in Google Scholar
van der Laan, G., and Figueroa, A.L. (2014) X-ray magnetic circular dichroism–A valuable tool to study magnetism. Coordination Chemistry Reviews, 277–278, 95–129.10.1016/j.ccr.2014.03.018Search in Google Scholar
van der Laan, G., and Kirkman, I.W. (1992) The 2p absorption spectra of 3d transition metal compounds in tetrahedral and octahedral symmetry. Journal of Physics: Condensed Matter, 4, 4189–4204.Search in Google Scholar
van der Laan, G., and Thole, B.T. (1991) Strong magnetic X-ray dichroism in 2p absorption spectra of 3d transition metal ions. Physical Review B, 43, 13401–13411.10.1103/PhysRevB.43.13401Search in Google Scholar
Verwey, E.J., Haayman, P.W., and Romeijn, F.C. (1947) Physical properties and cation arrangement of oxides with spinel structures. II. Electronic conductivity. Journal of Chemical Physics, 15, 181–187.10.1063/1.1746466Search in Google Scholar
Waerenborgh, J.C., Figueiredo, M.O., Cabral, J.M.P., and Pereira, L.C.J. (1994) Powder XRD structure refinements and 57Fe Mössbauer effect study of synthetic Zn1–xFexAl2O4 (0 < x ≤ 1) spinels annealed at different temperatures. Physics and Chemistry of Minerals, 21, 460–468.10.1007/BF00202276Search in Google Scholar
Waychunas, G.A. (1991) Crystal chemistry of oxides and oxyhydroxides. Reviews in Mineralogy, 25, 11–68.Search in Google Scholar
Wissmann, S., Wurmb, V.v., Litterst, F.J., Dieckmann, R., and Becker, K.D. (1998) The temperature dependent cation distribution in magnetite. Journal Physics and Chemistry of Solids, 59, 321–330.10.1016/S0022-3697(97)00219-9Search in Google Scholar
Wu, C.C., and Mason, T.O. (1981) Thermopower measurement of cation distribution in magnetite. Journal of the American Ceramic Society, 64, 520–522.10.1111/j.1151-2916.1981.tb10317.xSearch in Google Scholar
Yamanaka, T., and Takéuchi, Y. (1983) Order–disorder transition in MgAl2O4 spinel at high temperatures up to 1700 °C. Zeitshrift für Krisallographie, 165, 65–78.10.1524/zkri.1983.165.14.65Search in Google Scholar
Zhu, X., Kilirai, S.S., Hitchcock, A.P., and Bazylinski, D.A. (2015) What is the correct Fe L2,3 X ray absorption spectrum of magnetite? Journal of Electron Spectroscopy and Related Phenomena, 199, 19–26.10.1016/j.elspec.2014.12.005Search in Google Scholar
© 2016 by Walter de Gruyter Berlin/Boston