Physics and Chemistry of Minerals

, Volume 23, Issue 4–5, pp 248–262 | Cite as

Magnetic properties of microcrystalline iron (III) oxides and related materials as reflected in their Mössbauer spectra

  • E. Murad
Original Paper/Topic 4


Iron (III) oxides are common constituents of geologic materials, they are products and by-products of many industrial processes, they are involved in biological processes, and they are the outcome of iron and steel corrosion. In many of these examples the iron oxides are — fortuitously or intentionally — of small particle size, and as a consequence difficult, if not impossible, to characterize by standard physicochemical techniques. 57Fe Mössbauer spectroscopy is suitable for this purpose because it can serve as a probe of the electric and magnetic conditions in the vicinity of iron nuclei in solid samples, no matter how the iron may be bound.

Deviations of the magnetic properties of iron oxides of small particle size from those of their bulk counterparts lead to radical changes in the appearance of their Mössbauer spectra. Diverse models that have been put forward to account for such changes are discussed in this paper, including superparamagnetism, collective magnetic excitations, anomalous recoil-free fractions, superferromagnetism, spin canting and speromagnetism, reduced hyperfine field supertransfer, and Néel temperature reductions and distributions. Specific examples of microcrystalline iron (III) oxides and related minerals originating from different natural environments, resulting from technical processes, and being studied as planetary analogs are presented and discussed in the light of present-day knowledge on the properties of such materials.


Iron Magnetic Property Iron Oxide Magnetic Condition Small Particle Size 
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  1. Afanas'ev AM, Gorobchenko VD (1974) Resonant scattering of Mössbauer gamma quanta under relaxation conditions. Sov Phys JETP 40:1114–1120Google Scholar
  2. Agresti DG, Morris RV, Wills EL, Shelfer TD, Pimperl MM, Shen M-H, Clark BC, Ramsey BD (1992) Extraterrestrial Mössbauer spectroscopy. Hyperfine Interact 72:285–298Google Scholar
  3. Aharoni A (1992) Relaxation processes in small particles. In: Dormann JL, Fiorani D (eds) Magnetic Properties of Fine Particles: 3–11. North-Holland/Elsevier, AmsterdamGoogle Scholar
  4. Aharoni A (1994) Elongated superparamagnetic particles. J Appl Phys 75:5891–5893Google Scholar
  5. American Institute of Physics (1995) Phys Today 48 (4): 24–63Google Scholar
  6. Annersten H, Hafner SS (1973) Vacancy distribution in synthetic spinels of the series Fe3O4-γ-Fe2O3. Z Kristallogr 137:321–340Google Scholar
  7. Awschalom DD, Di Vincenzo DP (1995) Complex dynamics of mesoscopic magnets. Phys Today 48 (4): 43–48Google Scholar
  8. Balko B, Hoy GR (1974) Time-dependent effects using selectiveexcitation double-Mössbauer techniques with application to α-Fe2O3. Phys Rev B 10:36–49Google Scholar
  9. Bauminger ER, Nowik I (1989) Magnetism in plant and mammalian ferritin. Hyperfine Interact 50:484–498Google Scholar
  10. Bender Koch C, Mørup S (1991) Identification of green rust in an ochre sludge. Clay Mineral 26:577–582Google Scholar
  11. Bender Koch C, Oxborrow CA, Mørup S, Madsen MB, Quinn AJ, Coey JMD (1995) Magnetic properties of feroxyhyte (δ-FeOOH). Phys Chem Minerals 22:333–341Google Scholar
  12. Bigham JM, Carlson L, Murad E (1994) Schwertmannite, a new iron oxyhydroxysulphate from Pyhäsalmi, Finland, and other localities. Mineral Mag 58: 641–648Google Scholar
  13. Bishop JL, Murad E (1996) Schwertmannite on Mars? Spectroscopic analyses of Schwertmannite, its relationships to other ferric minerals, and its possible presence on the surface of Mars. In: Dyar MD, McCammon CA, Shaefer MW (eds) Mineral Spectroscopy: a Tribute to Roger G. Burns: in press. Geochem SocGoogle Scholar
  14. Bishop JE, Pieters CM, Burns RG, Edwards JO, Mancinelli RE, Fröschl H (1995) Reflectance spectroscopy of ferric sulfatebearing montmorillonites as Mars soil analog materials. Icarus 117:101–119Google Scholar
  15. Bocquet S, Kennedy SJ (1992) The Néel temperature of fine particle goethite. J Magnet Magn Mat 109:260–264Google Scholar
  16. Bocquet S, Pollard RJ, Cashion JD (1992) Dynamic magnetic phenomena in fine-particle goethite. Phys Rev B 46:11657–11664Google Scholar
  17. Bocquet S, Pollard RJ, Cashion JD (1995) Shape anisotropy in antiferromagnetic superparamagnetic particles. J Appl Phys 77:2809–2810Google Scholar
  18. Bowen EH, De Grave E, Vandenberghe RE (1993) Mössbauer effect studies of magnetic soils and sediments. In: Eong GJ, Grandjean F (eds) Mössbauer Spectroscopy Applied to Magnet Mat Sci 115–159. Plenum Press, New YorkGoogle Scholar
  19. Bowen EH, De Grave E, Bryan AM (1994) Mössbauer studies in an external field of well-crystallized Al-maghemites made from hematite. Hyperfine Interact 94:1977–1982Google Scholar
  20. Burns RG (1993) The MSATT workshop on chemical weathering on Mars. Geochim Cosmochim Acta 57:4551–4554Google Scholar
  21. Burns RG, Fisher DS (1990) Iron-sulfur mineralogy of Mars: magmatic evolution and chemical weathering products. J Geophys Res B 95:14115–14421Google Scholar
  22. Cardile CM (1990) Tetrahedral Fe3+ in ferrihydrite: 57Fe Mössbauer spectroscopic evidence. Clays Clay Miner 36: 537–539Google Scholar
  23. Cashion JD, Cook PS, Brown EJ (1986) Minerals, sediments and coals. Hyperfine Interact 27:23–34Google Scholar
  24. Chadwick JC, Jones DH, Thomas MF, Devenish M (1986) Superparamagnetism in an aluminium substituted ferrihydrite. Hyperfine Interact 28:537–540Google Scholar
  25. Chambaere D, De Grave E (1984) On the Néel temperature of β-FeOOH: structural dependence and its implications. J Magnetism Magnet Mat 42:263–268Google Scholar
  26. Childs CW (1992) Ferrihydrite: a review of structure, properties and occurrence in relation to soils. Z Pflanzenernähr Bodenkunde 155:441–448Google Scholar
  27. Childs CW, Goodman BA, Paterson E, Woodhams FWD (1980) The nature of iron in akaganéite. Austr J Chem 33:15–26Google Scholar
  28. Childs CW, Dickson DPE, Goodman BA, Lewis DG (1984) Mössbauer parameters for ferrihydrites at 4 K. Austr J Soil Res 22:149–154Google Scholar
  29. Chukhrov FV, Zvyagin BB, Ermilova EP, Gorshkov AI (1973) New data on iron oxides in the weathering zone. In: Serratosa JM (ed) Proceedings of the International Clay Conference —Madrid 1972: 333–341. Division de Ciencias C.S.I.C., MadridGoogle Scholar
  30. Cianchi L, Mancini M, Spina G, Tang H (1992) Mössbauer spectra of ferrihydrite: superferromagnetic interactions and anisotropy local energy. J Phys Condens Matter 4: 2073–2077Google Scholar
  31. Coey JMD (1971) Non-collinear spin arrangement in ultrafine ferrimagnetic crystallites. Phys Rev Lett 27: 1140–1142Google Scholar
  32. Coey JMD (1984) Mössbauer spectroscopy of silicate minerals. In: Long GJ (ed) Mössbauer Spectroscopy Applied to Inorganic Chemistry 1:443–509. Plenum Press, New YorkGoogle Scholar
  33. Coey JMD, Readman PW (1973a) Characterization and magnetic properties of natural ferric gel. Earth Planet Sci Eett 21:45–51Google Scholar
  34. Coey JMD, Readman PW (1973b) New spin structure in an amorphous ferric gel. Nature 246:476–478Google Scholar
  35. Coey JMD, Morrish AH, Sawatzky GA (1971) A Mössbauer study of conduction in magnetite. J Physique 32 C 1:271–273Google Scholar
  36. da Costa GM (1995) Mössbauer spectroscopy and X-ray diffraction studies of maghemite (γ-Fe2O3) and aluminum-substituted maghemites [γ-(Fe1-yAly)2O3] with 0.0≤y≤0.66. Ph. D. Thesis, 182 p. Universiteit GentGoogle Scholar
  37. da Costa GM, De Grave E, Bowen EH, Vandenberghe RE, de Bakker PMA (1994) The center shift in Mössbauer spectra of maghemite and aluminum maghemites. Clays Clay Min 42:628–633Google Scholar
  38. Daniels JM, Rosencwaig A (1969) Mössbauer spectroscopy of stoichiometric and non-stoichiometric magnetite. J Phys Chem Solids 30: 1561–1571Google Scholar
  39. de Bakker PMA, De Grave E, Persoons RM, Bowen EH, Vandenberghe RE (1990) An improved, two-parameter distribution method for the description of the Mössbauer spectra of magnetic small particles in an applied field. Meas Sci Technol 1:954–964Google Scholar
  40. De Grave E, Vandenberghe RE (1986) 57Fe Mössbauer effect study of well-crystallized goethite (α-FeOOH). Hyperfine Interact 28:643–646Google Scholar
  41. De Grave E, Vandenberghe RE (1990) Mössbauer effect study of the spin structure in natural hematites. Phys Chem Minerals 17:344–352Google Scholar
  42. De Grave E, Bowen EH, Weed SB (1982) Mössbauer study of aluminum-substituted hematite. J Magnetism Magnetic Mater 27:98–108Google Scholar
  43. De Grave E, Persoons RM, Chambaere DG, Vandenberghe RE, Bowen EH (1986) An 57Fe Mössbauer effect study of poorly crystalline γ-FeOOH. Phys Chem Miner 13:61–67Google Scholar
  44. De Grave E, Vandenberghe RE, Bowen EH (1990) Magnetic properties of some selected, soil-related iron oxides and oxyhydroxides as probed by 57Fe Mössbauer spectroscopy. In: Stanek J, Pedziwiatr AT (eds) Condensed Matter Studies by Nuclear Methods: 186–239. World Scientific, SingaporeGoogle Scholar
  45. De Grave E, de Bakker PMA, Bowen EH, Vandenberghe RE (1992) Effect of crystallinity and Al substitution on the applied-field Mössbauer spectra of iron oxides and oxyhydroxides. Z Pflanzenernähr Bodenkunde 155:467–472Google Scholar
  46. Dormann JE, Fiorani D, eds (1992) Magnetic Properties of Fine Particles. 430 p. North-Holland/Elsevier, AmsterdamGoogle Scholar
  47. Drits VA, Sakharov BA, Salyn AE, Manceau A (1993) Strutural model for ferrihydrite. Clay Min 28:185–207Google Scholar
  48. Eggleton RA, Fitzpatrick RW (1988) New data and a revised structural model for ferrihydrite. Clays Clay Min 36: 111–124Google Scholar
  49. Evans BJ (1973) Electrical conductivity and hyperfine interactions in MxFe3-xO4 above and below TN. AIP Conference Proceedings No. 10 (18th Annual Conference on Magnetism and Magnetic Materials — Denver 1972): 1398–1402. American Institute of Physics, New YorkGoogle Scholar
  50. Fanning DS, Rabenhorst MC, May L, Wagner DP (1989) Oxidation state of iron in glauconite from oxidized and reduced zones of soil-geologic columns. Clays Clay Min 37:59–64Google Scholar
  51. Faßbinder J, Stanjek H, Vali H (1989) Occurrence of magnetic bacteria in soil. Nature 343: 161–163Google Scholar
  52. Faurschou Hviid S, Agerkvist DP, Olsen M, Bender Koch C, Madsen MB (1994) Heated nontronite: possible relations to the magnetic phase in the Martian soil. Hyperfine Interact 91:529–533Google Scholar
  53. Forsyth JB, Hedley IG, Johnson CE (1968) The magnetic structure and hyperfine field of goethite (α-FeOOH). J Phys C 1: 179–188Google Scholar
  54. Fysh SA, Clark PE (1982) Aluminous hematite: a Mössbauer study. Phys Chem Minerals 8:257–267Google Scholar
  55. Ganguly B, Huggins FE, Feng Z, Huffman GP (1994) Anomalous recoilless fraction of 30-A-diameter FeOOH particles. Phys Rev B 49:3036–3042Google Scholar
  56. Häggström L, Annersten H, Ericsson T, Wäppling R, Karner W, Bjarman S (1978) Magnetic dipolar and electric quadrupolar effects on the Mössbauer spectra of magnetite above the Verwey transition. Hyperfine Interact 5:201–214Google Scholar
  57. Hargraves RB, Collinson DW, Arvidson RE, Spitzer CR (1977) The Viking magnetic properties experiment: primary mission results. J Geophys Res 82:4547–4558Google Scholar
  58. Heiman ND, Walker JC, Pfeiffer F (1969) Selective excitation of nuclear sublevels. Phys Rev 184:281–284Google Scholar
  59. Janot C, Gibert H, Tobias C (1973) Caractérisation de kaolinites ferrifères par spectrométrie Mössbauer. Bull Soc franç Miner Crist 96: 281–291Google Scholar
  60. Jing J, Zhao F, Yang X, Gonser U (1990) Magnetic relaxation in nanocrystalline iron-oxides. Hyperfine Interact 54:571–576Google Scholar
  61. Johnson CE (1969) Antiferromagnetism of γ FeOOH: a Mössbauer effect study. J Phys C 2:1996–2002Google Scholar
  62. Knudsen JM, Madsen MB, Olsen M, Vistisen L, Koch CB, Mørup S, Kankeleit E, Klingelhöfer G, Evlanov EN, Khromov VN, Mukhin LM, Prilutski OF, Zubkov B, Smirnov GV, Juchniewicz J (1991) Mössbauer spectroscopy on the surface of Mars. Why? Hyperfine Interact 68: 83–94Google Scholar
  63. Koch CJM, Borggaard OK, Madsen MB, Mørup S (1987) Magnetic properties of synthetic feroxyhite (δ'-FeOOH). In: Schultz LG, van Olphen H, Mumpton FA (eds) Proceedings of the International Clay Conference — Denver 1985:212–220. The Clay Minerals Society, Bloomington, IndianaGoogle Scholar
  64. Kündig W, Hargrove RS (1969) Electron hopping in magnetite. Solid State Comm 7:223–227Google Scholar
  65. Madsen MB, Mørup S, Koch CJW (1986) Magnetic properties of ferrihydrite. Hyperfine Interact 27: 329–332Google Scholar
  66. Madsen MB, Agerkvist DP, Gunnlaugsson HP, Faurschou Hviid S, Knudsen JM, Vistisen L (1995) Titanium and the magnetic phase on Mars. Hyperfine Interact 95:291–304Google Scholar
  67. Manceau A, Combes J-M, Calas G (1990) New data and a revised structural model for ferrihydrite: comment. Clays Clay Miner 38:331–334Google Scholar
  68. Mathalone Z, Ron M, Biran A (1970) Magnetic ordering in iron gel. Solid State Comm 8: 333–336Google Scholar
  69. McCammon CA, De Grave E, Pring A (1996) The magnetic structure of bemalite, Fe(OH)3. J Magnetism Magnetic Mater, 162:33–39Google Scholar
  70. McCammon CA, Pring A, Keppler H, Sharp T (1995) A study of bermalite, Fe(OH)3, using Mössbauer spectroscopy, optical spectroscopy and transmission electron microscopy. Phys Chem Miner 22:11–20Google Scholar
  71. Meisel W (1975) Some analytical aspects of the Mössbauer spectrometry. 5th International Conference on Mössbauer Spectroscopy — Bratislava 1973, Proceedings 1:200–213. Czechoslovak Atomic Energy Commission, PragueGoogle Scholar
  72. Mitra S, Pal T, Pal T (1991) Variation in Mössbauer hyperfine parameters with Al-substitution in iron oxide and hydroxide phases. Indian J Pure Appl Phys 29:313–325Google Scholar
  73. Mizota M, Maeda Y (1986) Magnetite in the radular teeth of chitons. Hyperfine Interact 29:1423–1426Google Scholar
  74. Mohie-Eldin M-EY, Frankel RB, Gunther L, Papaefthymiou GC (1995) The anomalous Mössbauer fraction of ferritin and polysaccharide iron complex (PIC). Hyperfine Interact 96:111–138Google Scholar
  75. Morris RV, Agresti DG, Lauer HV Jr, Newcomb JA, Shelfer TD, Murali AV (1989) Evidence for pigmentary hematite on Mars based on optical, magnetic, and Mössbauer studies of superparamagnetic (nanocrystalline) hematite. J Geophys Res B 94:2760–2778Google Scholar
  76. Morris RV, Lauer HV Jr, Schulze DG, Burns RG (1991) Preparation and characterization of a nanophase hematite powder. Lunar Planet Sci 22:927–928. Lunar and Planetary Institute, Houston, TexasGoogle Scholar
  77. Morris RV, Golden DC, Bell JF III, Lauer HV Jr, Adams JB (1993) Pigmenting agents in Martian soils: inferences from spectral, Mössbauer, and magnetic properties of nanophase and other iron oxides in Hawaiian palagonitic soil PN-9. Geochim Cosmochim Acta 57:4597–4609Google Scholar
  78. Morris RV, Ming DW, Golden DC, Bell JF III (1996) An occurrence of jarositic tephra on Mauna Kea, Hawaii: implications for the ferric mineralogy of the Martian surface. In: Dyar MD, McCammon CA, Shaefer MW (eds) Mineral Spectroscopy: a Tribute to Roger G. Burns: in press. Geochem SocGoogle Scholar
  79. Morrish AH, Haneda K, Schurer PJ (1976) Surface magnetic structure of small γ-Fe2O3 particles. J Physique 37 C 6: 301–305Google Scholar
  80. Mørup (1983) Magnetic hyperfine splitting in Mössbauer spectra of microcrystals. J Magnet Mag Mat 37:39–50Google Scholar
  81. Mørup (1990) Mössbauer effect in small particles. Hyperfine Interact 60:959–974Google Scholar
  82. Mørup S, Topsøe H (1976) Mössbauer studies of thermal excitations in magnetically ordered microcrystals. Appl Phys 11:63–66Google Scholar
  83. Mørup S, Madsen MB, Franck J, Villadsen J, Koch CJW (1983) A new interpretation of Mössbauer spectra of microcrystalline goethite: “super-ferromagnetism” or “super-spin-glass” behaviour? J Magnet Mag Mat 40:163–174Google Scholar
  84. Murad E (1979) Mössbauer and X-ray data on β-FeOOH (akaganéite). Clay Mineral 14:273–283Google Scholar
  85. Murad E (1982) Ferrihydrite deposits on an artesian fountain in lower Bavaria. N Jb Min Mh: 45–56Google Scholar
  86. Murad E (1984) High-precision determination of magnetic hyperfine fields by Mössbauer spectroscopy using an internal standard. J Phys E 17:736–737Google Scholar
  87. Murad E (1988a) Properties and behavior of iron oxides as determined by Mössbauer spectroscopy. In: Stucki JW, Goodman BA, Schwertmann U (eds) Iron in Soils and Clay Minerals: 309–350. Reidel, Dordrecht/BostonGoogle Scholar
  88. Murad E (1988b) The Mössbauer spectrum of “well”-crystallized ferrihydrite. J Magnet Mag Mat 74:153–157Google Scholar
  89. Murad E (1989) Poorly-crystalline minerals and complex mineral assemblages. Hyperfine Interact 47: 33–53Google Scholar
  90. Murad E (1990) Application of 57Fe Mössbauer spectroscopy to problems in clay mineralogy and soil science: possibilities and limitations. Adv Soil Sci 12:125–157Google Scholar
  91. Murad E (1992) Magnetic properties of fine-grained minerals. In: Dormann JL, Fiorani D (eds) Magnetic Properties of Fine Particles: 339–349. North-Holland/Elsevier, AmsterdamGoogle Scholar
  92. Murad E (1994) Some recent developments in the study of soils by Mössbauer spectroscopy. 15th World Congress of Soil Science — Acapulco 1994, Transactions 8a: 85–93. Instituto Nacional de Estadistica, Geografia e Informatica, MexicoGoogle Scholar
  93. Murad E, Johnston JH (1987) Iron oxides and oxyhydroxides. In: Long GJ (ed) Mössbauer Spectroscopy Applied to Inorganic Chemistry 2: 507–582. Plenum Press, New YorkGoogle Scholar
  94. Murad E, Schwertmann U (1980) The Mössbauer spectrum of ferrihydrite and its relations to those of other iron oxides. Am Mineral 65:1044–1049Google Scholar
  95. Murad E, Schwertmann U (1983) The influence of aluminium substitution and crystallinity on the Mössbauer spectra of goethite. Clay Mineral 18:301–312Google Scholar
  96. Murad E, Schwertmann U (1984) The influence of crystallinity on the Mössbauer spectrum of lepidocrocite. Mineral Mag 48:507–511Google Scholar
  97. Murad E, Schwertmann U (1986) Influence of Al substitution and crystallinity on the room-temperature Mössbauer spectrum of hematite. Clays Clay Mineral 34:1–6Google Scholar
  98. Murad E, Schwertmann U (1993) Temporal stability of a finegrained magnetite. Clays Clay Mineral 41:111–113Google Scholar
  99. Murad E, Taylor RM (1986) The oxidation of hydroxycarbonate green rusts. In: Long GJ, Stevens JG (eds) Industrial Applications of the Mössbauer Effect:585–593. Plenum Press, New YorkGoogle Scholar
  100. Murad E, Wagner U (1989) Pure and impure clays and their firing products. Hyperfine Interact 45: 161–177Google Scholar
  101. Murad E, Wagner U (1991) Mössbauer spectra of kaolinite, halloysite and the firing products of kaolinite: new results and a reappraisal of published work. N Jb Min Abh 162:281–309Google Scholar
  102. Murad E, Wagner U (1994) The Mössbauer spectrum of illite. Clay Mineral 29:1–10Google Scholar
  103. Murad E, Wagner U (1996) The thermal behaviour of an Fe-rich illite. Clay Mineral 31:45–52Google Scholar
  104. Murad E, Bowen LH, Long GJ, Quin TG (1988) The influence of crystallinity on magnetic ordering in natural ferrihydrites. Clay Mineral 23:161–173Google Scholar
  105. Néel L (1949) Théorie du trainage magnétique des ferromagnétiques en grains fins avec application aux terres cuites. Ann Géophys 5:99–136Google Scholar
  106. Pankhurst QA, Pollard RJ (1991) Origin of the spin-canting anomaly in small ferrimagnetic particles. Phys Rev Lett 67:248–250Google Scholar
  107. Pankhurst QA, Pollard RJ (1992) Structural and magnetic properties of ferrihydrite. Clays Clay Mineral 40:268–272Google Scholar
  108. Pollard RJ, Cardile CM, Lewis DG, Brown LJ (1992) Characterization of FeOOH polymorphs and ferrihydrite using low-temperature, applied-field, Mössbauer spectroscopy. Clay Mineral 27:57–71Google Scholar
  109. Pollard RJ, Morrish AH (1987) High-field magnetism in non-polar γ-Fe2O3 recording particles. IEEE Trans Magnetics MAG 23: 42–44Google Scholar
  110. Prené P, Tronc E, Jolivet JP, Livage J, Cherkaoui R, Noguès M, Dormann JL (1994) Mössbauer investigation of non-aggregated γ-Fe2O3 particles. Hyperfine Interact 93:1409–1414Google Scholar
  111. Rancourt DG (1994) Mössbauer spectroscopy of minerals. II. Problem of resolving cis and trans octahedral Fe2+ sites. Phys Chem Minerals 21:250–257Google Scholar
  112. Rancourt DG, Daniels JM (1984) Influence of unequal magnetization direction probabilities on the Mössbauer spectra of superparamagnetic particles. Phys Rev B 29:2410–2414Google Scholar
  113. Rancourt DG, Dang M-Z, Lalonde AE (1992) Mössbauer spectroscopy of tetrahedral Fe3+ in trioctahedral micas. Am Mineral 77:34–43Google Scholar
  114. Rodmacq B (1984) Superparamagnetic properties of small iron hydroxide precipitates in ion exchange membranes. J Phys Chem Sol 45:1119–1127Google Scholar
  115. Ruppin R (1970) Recoilless fraction in microcrystals. Phys Rev B 2:1229–1235Google Scholar
  116. Stanjek H, Weidler PG (1992) The effect of dry heating on the chemistry, surface area, and oxalate solubility of synthetic 2- line and 6-line ferrihydrites. Clay Mineral 27:397–412Google Scholar
  117. Taylor RM, Maher BA, Self PG (1987) Magnetite in soils: I. The synthesis of single-domain and superparamagnetic magnetite. Clay Mineral 22:411–422Google Scholar
  118. Toulmin P III, Baird AK, Clark BC, Keil K, Rose HJ Jr, Christian RP, Evans PH, Kelliher WC (1977) Geochemical and mineralogical interpretation of the Viking inorganic chemical results. J Geophys Res 82:4625–4634Google Scholar
  119. Towe KM (1990) Phosphorus and the ferritin iron core: functionbalanced biomineralization. In: Crick RE (ed) Origin, Evolution, and Modern Aspects of Biomineralization in Plants and Animals: 265–272. Plenum Press, New YorkGoogle Scholar
  120. Towe KM, Bradley WF (1967) Mineralogical constitution of colloidal “hydrous ferric oxides”. J Colloid Interf Sci 24:384–392Google Scholar
  121. Tronc E, Prene P, Jolivet JP, d'Orazio F, Lucari F, Fiorani D, Godinho M, Cherkaoui R, Nogues M, Dormann JL (1995) Magnetic behaviour of γ-Fe2O3 nanoparticles by Mössbauer spectroscopy and magnetic measurements. Hyperfine Interact 95:129–148Google Scholar
  122. Vandenberghe RE, De Grave E (1989) Mössbauer effect studies of oxidic spinels. In: Long GJ and Grandjean F (eds) Mössbauer Spectroscopy Applied to Inorganic Chemistry 3:59–182. Plenum Press, New YorkGoogle Scholar
  123. Vandenberghe RE, De Grave E, Landuyt C, Bowen LH (1990) Some aspects concerning the characterization of iron oxides and hydroxides in soils and clays. Hyperfine Interact 53:175–196Google Scholar
  124. van der Giessen AA (1966) The structure of iron (III) oxide-hydrate gels. J Inorg Nucl Chem 28:2155–2159Google Scholar
  125. van der Kraan AM (1973) Mössbauer effect studies of surface ions of ultrafine α-Fe2O3 particles. Phys Stat Sol A 18: 215–226Google Scholar
  126. van Wieringen JS (1968) Note of Mössbauer fraction in powders of small particles. Phys Lett A 26:370–371Google Scholar
  127. Wagner U, Knorr W, Forster A, Murad E, Salazar R, Wagner FE (1988) Mössbauer study of illite associated with iron oxi-hydroxides. Hyperfine Interact 41: 855–858Google Scholar
  128. Webb J, St Pierre TG (1989) The use and potential of Mössbauer spectroscopy in studies of biological mineralization. In: Long GJ, Grandjean F (eds) Mössbauer Spectroscopy Applied to Inorganic Chemistry 3:417–444. Plenum Press, New YorkGoogle Scholar

Copyright information

© Springer-Verlag 1996

Authors and Affiliations

  • E. Murad
    • 1
  1. 1.Bayerisches Geologisches LandesamtBambergGermany

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