Article
Licensed
Unlicensed Requires Authentication

Determination of nanoparticulate magnetite stoichiometry by Mössbauer spectroscopy, acidic dissolution, and powder X-ray diffraction: A critical review

  • and EMAIL logo
Published/Copyright: April 2, 2015
Become an author with De Gruyter Brill
Author Information
American Mineralogist
From the journal American Mineralogist Volume 95 Issue 7

Abstract

A solid solution can exist of magnetite (Fe3O4) and maghemite (γ-Fe2O3), which is commonly referred to as nonstoichiometric or partially oxidized magnetite. The degree of stoichiometry in magnetite is quantitatively measured by determining the ratio of Fe2+ to Fe3+. Magnetite stoichiometry (x = Fe2+/Fe3+) strongly influences several physical properties, including the coercitivity, sorption capacity, reduction potential, and crystalline structure. Magnetite stoichiometry has been extensively studied, although very little work exists examining the stoichiometry of nanoparticulate samples (<<100 nm); when the stoichiometry was measured for nanoparticulate samples, it was not validated with a secondary technique. Here, we review the three most common techniques to determine magnetite stoichiometry: (1) acidic dissolution; (2) Mössbauer spectroscopy; and (3) powder X-ray diffraction (pXRD), specifically with nanoparticulate samples in mind. Eight samples of nonstoichiometric magnetite were synthesized with x ranging from 0 to 0.50 and with the particle size kept as similar as possible (BET specific surface area = 63 ± 7 m2/g; particle size ≈ 20 nm). Our measurements indicate excellent agreement between stoichiometries determined from Mössbauer spectra and by acidic dissolution, suggesting that Mössbauer spectroscopy may be a useful means for estimating magnetite stoichiometry in nanoparticulate, multi-phases samples, such as those found in the environment. A significant linear correlation was also observed between the unit-cell length (a) of magnetite measured by pXRD and magnetite stoichiometry, indicating that pXRD may also be useful for determining particle stoichiometry, especially for mixed phased samples

Keywords: Magnetite; maghemite; magnetite oxidation; nonstoichiometric magnetite; nanoparticle; Mössbauer spectroscopy; stoichiometry; X-ray diffraction
Received: 2009-10-26
Accepted: 2010-2-9
Published Online: 2015-4-2
Published in Print: 2010-7-1

© 2015 by Walter de Gruyter Berlin/Boston

Articles in the same Issue

  1. Corundum–leucosome-bearing aluminous gneiss from Ayyarmalai, Southern Granulite Terrain, India: A textbook example of vapor phase-absent muscovite-melting in silica-undersaturated aluminous rocks
  2. Near infrared spectra of white mica in the Belt Supergroup and implications for metamorphism
  3. Arsenic speciation in fluid inclusions using micro-beam X-ray absorption spectroscopy
  4. The crystal chemistry and crystal structure of kuksite, Pb3Zn3Te6+P2O14, and a note on the crystal structure of yafsoanite, (Ca,Pb)3Zn(TeO6)2
  5. Chabazite-Mg: a new natural zeolite of the chabazite series
  6. Solution calorimetric investigation of fluor-chlorapatite crystalline solutions
  7. Pertsevite-(OH), a new mineral in the pertsevite series, Mg2(BO3)1–x(SiO4)x(F,OH)1–x (x < 0.5), from the Snezhnoye deposit in Sakha-Yakutia Republic, Russia
  8. Bitikleite-(SnAl) and bitikleite-(ZrFe): New garnets from xenoliths of the Upper Chegem volcanic structure, Kabardino-Balkaria, Northern Caucasus, Russia
  9. Silicon coordination in rutile and TiO2-II at ambient and high pressures: Si-29 NMR
  10. Spin orientation in a natural Ti-bearing hematite: Evidence for an out-of-plane component
  11. Theoretical determination of the Raman spectra of single-crystal forsterite (Mg2SiO4)
  12. Nitrogen and hydrogen isotope compositions and solubility in silicate melts in equilibrium with reduced (N+H)-bearing fluids at high pressure and temperature: Effects of melt structure
  13. In situ ultrasonic velocity measurements across the olivine-spinel transformation in Fe2SiO4
  14. The computation of equilibrium assemblage diagrams with Theriak/Domino software
  15. Determination of nanoparticulate magnetite stoichiometry by Mössbauer spectroscopy, acidic dissolution, and powder X-ray diffraction: A critical review
  16. Low-temperature behavior of natural kalsilite with P31c symmetry: An in situ single-crystal X-ray diffraction study
  17. First-principles simulations of MgO tilt grain boundary: Structure and vacancy formation at high pressure
  18. The effect of oxo-component on the high-pressure behavior of amphiboles
  19. Integral molar absorptivities of OH in muscovite at 20 to 650 °C by in-situ high-temperature IR microspectroscopy
  20. Principles of thermal expansion in the feldspar system
  21. A moissanite cell apparatus for optical in situ observation of crystallizing melts at high temperature
  22. Polezhaevaite-(Ce), NaSrCeF6, a new mineral from the Khibiny massif (Kola Peninsula, Russia)
  23. The interlayer structure of trioctahedral lithian micas: An AXANES spectroscopy study at the potassium K-edge
  24. Amorphous Materials: Properties, Structure, and Durability. Arsenic enrichment in hydrous peraluminous melts: Insights from femtosecond laser ablation-inductively coupled plasma-quadrupole mass spectrometry, and in situ X-ray absorption fine structure spectroscopy
  25. Letter. Partial high-grade alteration of monazite using alkali-bearing fluids: Experiment and nature
  26. Letter. A first-principles determination of the orientation of H3O+ in hydronium alunite
  27. Letter. The structure of a super-aluminous version of the dense hydrous-magnesium silicate phase D
  28. Letter. Kaolin polytypes revisited ab initio at 10 GPa
https://doi.org/10.2138/am.2010.3435
Keywords for this article
Magnetite; maghemite; magnetite oxidation; nonstoichiometric magnetite; nanoparticle; Mössbauer spectroscopy; stoichiometry; X-ray diffraction

Articles in the same Issue

  1. Corundum–leucosome-bearing aluminous gneiss from Ayyarmalai, Southern Granulite Terrain, India: A textbook example of vapor phase-absent muscovite-melting in silica-undersaturated aluminous rocks
  2. Near infrared spectra of white mica in the Belt Supergroup and implications for metamorphism
  3. Arsenic speciation in fluid inclusions using micro-beam X-ray absorption spectroscopy
  4. The crystal chemistry and crystal structure of kuksite, Pb3Zn3Te6+P2O14, and a note on the crystal structure of yafsoanite, (Ca,Pb)3Zn(TeO6)2
  5. Chabazite-Mg: a new natural zeolite of the chabazite series
  6. Solution calorimetric investigation of fluor-chlorapatite crystalline solutions
  7. Pertsevite-(OH), a new mineral in the pertsevite series, Mg2(BO3)1–x(SiO4)x(F,OH)1–x (x < 0.5), from the Snezhnoye deposit in Sakha-Yakutia Republic, Russia
  8. Bitikleite-(SnAl) and bitikleite-(ZrFe): New garnets from xenoliths of the Upper Chegem volcanic structure, Kabardino-Balkaria, Northern Caucasus, Russia
  9. Silicon coordination in rutile and TiO2-II at ambient and high pressures: Si-29 NMR
  10. Spin orientation in a natural Ti-bearing hematite: Evidence for an out-of-plane component
  11. Theoretical determination of the Raman spectra of single-crystal forsterite (Mg2SiO4)
  12. Nitrogen and hydrogen isotope compositions and solubility in silicate melts in equilibrium with reduced (N+H)-bearing fluids at high pressure and temperature: Effects of melt structure
  13. In situ ultrasonic velocity measurements across the olivine-spinel transformation in Fe2SiO4
  14. The computation of equilibrium assemblage diagrams with Theriak/Domino software
  15. Determination of nanoparticulate magnetite stoichiometry by Mössbauer spectroscopy, acidic dissolution, and powder X-ray diffraction: A critical review
  16. Low-temperature behavior of natural kalsilite with P31c symmetry: An in situ single-crystal X-ray diffraction study
  17. First-principles simulations of MgO tilt grain boundary: Structure and vacancy formation at high pressure
  18. The effect of oxo-component on the high-pressure behavior of amphiboles
  19. Integral molar absorptivities of OH in muscovite at 20 to 650 °C by in-situ high-temperature IR microspectroscopy
  20. Principles of thermal expansion in the feldspar system
  21. A moissanite cell apparatus for optical in situ observation of crystallizing melts at high temperature
  22. Polezhaevaite-(Ce), NaSrCeF6, a new mineral from the Khibiny massif (Kola Peninsula, Russia)
  23. The interlayer structure of trioctahedral lithian micas: An AXANES spectroscopy study at the potassium K-edge
  24. Amorphous Materials: Properties, Structure, and Durability. Arsenic enrichment in hydrous peraluminous melts: Insights from femtosecond laser ablation-inductively coupled plasma-quadrupole mass spectrometry, and in situ X-ray absorption fine structure spectroscopy
  25. Letter. Partial high-grade alteration of monazite using alkali-bearing fluids: Experiment and nature
  26. Letter. A first-principles determination of the orientation of H3O+ in hydronium alunite
  27. Letter. The structure of a super-aluminous version of the dense hydrous-magnesium silicate phase D
  28. Letter. Kaolin polytypes revisited ab initio at 10 GPa
Downloaded on 12.4.2026 from https://www.degruyterbrill.com/document/doi/10.2138/am.2010.3435/html
Scroll to top button