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Magnetic behaviour of trioctahedral mica-2M1 occurring in a magnetic anomaly zone

Published online by Cambridge University Press:  05 July 2018

S. Pini
Affiliation:
Dipartimento di Scienze Della Terra, Università di Modena e Reggio Emilia, Via S. Eufemia, 19, I-41100 Modena, Italy
M. Affronte
Affiliation:
Dipartimento di Fisica, Università di Modena e Reggio Emilia, Via G. Campi 213/a, I-41100 Modena, Italy
M. F. Brigatti*
Affiliation:
Dipartimento di Scienze Della Terra, Università di Modena e Reggio Emilia, Via S. Eufemia, 19, I-41100 Modena, Italy
*

Abstract

This work relates the crystal chemistry and the magnetic behaviour of a trioctahedral mica (chemical formula: (K0.90Na0.01Ca0.01Ba0.010.07)(Al0.05Fe2+1.10Mg1.38Ti0.32Mn0.010.04)(Al1.12Si2.88)O10 (F0.27OH1.27O0.46); unit cell parameters: a = 5.345(2) Å, b = 9.261(4) Å, c = 20.189(8) Å; β = 95.075(8)°) from Minto Block (Ungava peninsula, northern Quebec, Canada), a region characterized by high magnetic anomalies. Crystallographic and X-ray absorption spectroscopy data suggest a prevalent divalent oxidation state for Fe and a disordered Fe 2+ distribution in the two octahedral sites Ml and M2. The real part of magnetic susceptibility shows two peaks at ∼5.2 K and 120 K. However, as demonstrated by AC magnetic susceptibility measurements, the origin of the two effects is different: the peak position of the first one (i.e. the effect revealed at 5.2 K) is frequency-dependent, thus suggesting a spin-glass like behaviour. The effect at 120 K can instead be attributed to the occurrence of diluted phases in mica matrix, such as Fe oxides.

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

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References

Ballet, O. and Coey, J.M.D. (1982) Magnetic properties of sheet silicates; 2:1 layer minerals. Physics and Chemistry of Minerals, 8, 218229.CrossRefGoogle Scholar
Beausoleil, N., Lavallee, P., Yelon, A., Ballet, O. and Coey, J.M.D. (1983) Magnetic properties of biotite micas. Journal of Applied Physics, 54, 906915.CrossRefGoogle Scholar
Bigi, S. and Brigatti, M.F. (1994) Crystal chemistry and microstructures of plutonic biotite. American Mineralogist, 79, 6372.Google Scholar
Brigatti, M.F. and Guggenheim, S. (2002) Mica crystal chemistry and the influence of pressure, temperature, and solid solution on atomistic models. Pp. 198 in: Micas: Crystal Chemistry and Metamorphic Petrology (Mottana, A., Sassi, F.P., Thompson, J.B. Jr. and Guggenheim, S., editors). Reviews in Mineralogy and Geochemistry, 46, Mineralogical Society of America, Washington, D.C. and Geochemical Society, Washington, D.C. Google Scholar
Coey, J.M.D. and Ghose, S. (1988) Magnetic ordering and thermodynamics in silicates. Mathematical and Physical Sciences, Series C, 225, 459499.Google Scholar
Coey, J.M.D., Ballet, O., Moukarika, A. and Soubeyroux, J.L. (1981) Magnetic properties of sheet silicates; 1:1 layer minerals. Physics and Chemistry of Minerals, 7, 141148.CrossRefGoogle Scholar
Giuli, G., Paris, E., Wu, Z.Y., Brigatti, M.F., Cibin, G., Mottana, A. and Marcelli, A. (2001) Experimental and theoretical XANES and EXAFS study of tetra-ferriphlogopite. European Journal of Mineralogy, 13, 10991108.CrossRefGoogle Scholar
Gridin, V.V., Hearne, G.R. and Honig, J.M. (1996) Magnetoresistance extremum at the first-order Verwey transition in magnetite (Fe3O4). Physical Review B, 53, 1551815521.CrossRefGoogle Scholar
Hawthorne, F.C., Ungaretti, L. and Oberti, R. (1995) Site populations in minerals: terminology and presentation of results. The Canadian Mineralogist, 33, 907911.Google Scholar
Krause, M.O. and Oliver, J.H. (1979) Natural widths of atomic K and L Levels, Kα X-ray lines and several KLL Auger lines. Journal of Physical and Chemical Reference Data, 8, 329338.CrossRefGoogle Scholar
Laurora, A., Brigatti, M.F., Mottana, A., Malferrari, D. and Caprilli, E. (2007) Crystal chemistry of trioctahedral micas in alkaline and subalkaline volcanic rocks: A case study from Mt. Sassetto (Tolfa district, Latium, central Italy). American Mineralogist, 92, 468480.CrossRefGoogle Scholar
Meyrowitz, R. (1970) New semimicroprocedure for determination of ferrous iron in refractory silicate minerals using a sodium metafluoborate decomposition. Analytical Chemistry, 42, 11101113.CrossRefGoogle Scholar
Pilkington, M. and Percival, J.A. (1999) Crustal magnetization and long wavelength aeromagnetic anomalies of the Minto block, Quebec. Journal of Geophysical Research, 104, 75137526.CrossRefGoogle Scholar
Pilkington, M. and Percival, J.A. (2001) Relating crustal magnetization and satellite-altitude magnetic anomalies in the Ungava peninsula, northern Quebec, Canada. Earth and Planetary Science Letters, 194, 127133.CrossRefGoogle Scholar
Rancourt, D.G., Christie, I.A.D., Lamarche, G., Swainson, I. and Flandrois, S. (1994) Magnetism of synthetic and natural annite mica: ground state and nature of excitations in an exchange-wise two-dimensional easy-plane ferromagnet with disorder. Journal of Magnetism and Magnetic Materials, 138, 3144.CrossRefGoogle Scholar
Sheldrick, G.M. (1997) SHELX-97: a program for the solution and refinement of crystal structures. University of Göttingen, Göttingen, Germany.Google Scholar
Tabiś, W., Tarnawski, Z., Kąkol, Z., Król, G., Kołodziejczyk, A., Kozłowski, A., Fluerasu, A. and Honig, J.M. (2007) Magnetic and structural studies of magnetite at the Verwey transition. Journal of Alloys and Compounds, 442, 203205.CrossRefGoogle Scholar
Tarnawski, Z., Wiechec, A., Madej, M., Nowak, D., Owoc, D., Król, G., Kąkol, Z., Kolwicz-Chodak, L., Kozlowsi, A. and David, T. (2004) Studies of the Verwey transition in magnetite. Ada Physica PolonicaA, 106, 771775.CrossRefGoogle Scholar
Tombolini, F., Brigatti, M.F., Marcelli, A., Cibin, G., Mottana, A. and Giuli, G. (2002) Crystal chemical study by XANES of trioctahedral micas: the most characteristic layer silicates. International Journal of Modern Physics B, 16, 16731679.CrossRefGoogle Scholar
Waychunas, G.A., Apted, M.J. and Brown, G.E. Jr. (1983) X-ray i^-edge absorption spectra of Fe minerals and model compounds near-edge structure. Physics and Chemistry of Minerals, 10, 1 —9.CrossRefGoogle Scholar
Wilke, M., Farges, F., Petit, P.E., Brown, G.E. Jr. and Martin, F. (2001) Oxidation state and coordination of Fe in minerals: An Fe K-XANES spectroscopic study. American Mineralogist, 86, 714730.CrossRefGoogle Scholar
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Crystallographic coordinates

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Structure factors

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