Abstract
The infrared complex permittivity functions of three varieties of maghemite, γ-Fe2O3, having different degrees of vacancy ordering, have been determined from their IR reflectance spectra, measured at near to normal incidence on pressed powder pellets. The optical constants therefrom obtained have been verified by using them in the simulation of the corresponding absorption spectra for KBr-diluted pellets, and these are in excellent agreement with the experimental spectra. All calculations are based on a procedure for the estimation of the effective dielectric function of a mixture, which incorporates percolation features, recently developed by the authors.
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References
Born M, Huang K (1954) Dynamical Theory of Crystal Lattices. Oxford U.P., London
Boudeuille M, Batis-Landoulsi H, Leclercq CH, Vergnon P (1983) Structure of γ-Fe2O3 microcrystals: Vacancy distribution and superstructure. J Solid State Chem 48:21–32
Braun PB (1952) A superstructure in Spinels. Nature 170:1123
Degiorgi L, Blatter-Mörke I, Watcher P (1987) Magnetite: Phonon modes and the Verwey transition. Phys Rev 835:5421–5424
Dowty E (1987) Fully automated microcomputer calculation of vibrational spectra. Phys Chem Minerals 14:67–79
Genzel L, Martin TP (1972) Infrared absorption in small ionic crystals. Phys Stat Sol B 51:91–99
Gillot B, Benloucif RM (1992) X-Ray diffraction, IR spectrometry and high resolution electron microscopy on ordered zinc-substituted maghemites. Mater Chem Phys 32:37–41
Gillot B, Bouton F (1980) Correlation between IR spectra, X-Ray diffraction, and distribution of structural vacancies in 28–01-type spinels. J Solid State Chem 32:303–310
González-Carreño T, Mifsud A, Serna CJ, Palacios JM (1991) Preparation of homogeneous Zn/Co mixed oxides by spray pyrolysis. Mater Chem and Phys 27:287–296
González-Carreño T, Morales MP, Gracia M, Serna CJ (1993) Preparation of uniform γ-Fe2O3 particles with nanometer size by spray pyrolysis. Matter Lett 18:151–155
Greaves C (1983) A powder neutron investigation of vacancy ordering and covalence in γ-Fe2O3. J Solid State Chem 49:325–333
Greenwood NN (1970) Ionic Crystals, Lattice Defects and Non Stoichiometry. Butterworths, London, p 92
Haneda K, Morrish AH (1977) Vacancy ordering in γ-Fe2O3 small particles. Solid State Comm 22:779–782
Iglesias JE, Ocaña M, Serna CJ (1990) Aggregation and matrix effects on the infrared spectrum of microcrystalline powders. Appl Spectrosc 44:418–426
Ishii M, Nakahira M, Yamanaka T (1972) Infrared absorption spectra and cation distribution in (Mn, Fe)3O4. Solid State Comm 11:209–212
Katsnelson EZ, Karoza AG, Meleshschenko LA, Bashkirov LA (1989) IR Reflection spectra of Manganese-Zinc Ferrites. Phys Stat Sol (B) 152:657–66
Kryukova GN, Chuvilin AL, Sadykov VS (1990) On the γ-Fe2O3 superstructure observation by high resolution electron microscopy. J Solid State Chem 89:208–211
Landauer R (1952) The electrical resistance of binary metallic mixtures. J Appl Phys 23:779–784
Landauer R (1978) Electrical Transport and Optical Properties of Inhomogeneous Media. In: Garland JC, Tanner DB (eds) Proceedings of the First Conference on the Electrical Transport and Optical Properties of Inhomogeneous Media. AIP Conf Proc N∘ 40 (AIP, New York), p 2
Lefever RA (1970) Numerical Data and Functional Relationships in Science and Technology, Vol 4. In: Hellwege KH (ed) Magnetic and other Properties of Oxides and Related Compounds. Springer, Berlin, pg 18–20
Lutz HD, Müller B, Steiner HJ (1991) Lattice vibration spectra. LIX. Single crystal infrared and Raman studies of spinel type oxides. J Solid State Chem 90:54–60
Matijevic E, Scheiner P (1978) III. Preparation of uniform particles by hydrolysis of Fe(III)-Chloride-Nitrate, and-Perchlorate solutions. J Colloid Interface Sci, 63:509–524
Megaw HD (1972) Crystal Structures. WB Saunders Company, Philadelphia, p 221
Morales MP (1993) Efectos Morfológicos y Estructurales en las Propiedades Magnéticas de Partículas Uniformes de γ-Fe2O3. PhD Dissertation (in Spanish), UAM, Madrid
Morales MP, González-Carreño T, Serna CJ (1992) The formation of α-Fe2O3 monodispersed particles in solution. J Mater Res 7:2538–2545
Morales MP, Julián C, González JM, Serna CJ (1993) The effect of the distribution of vacancies on the magnetic properties of γ-Fe2O3 particles. J Mater Res 9:135–141
Morales MP, Pecharromán C, González-Carreño T, Serna CJ (1994) Structural characteristics of uniform γ-Fe2O3 particles with different axial (length/width) ratios. Journal of Solid State Chem 108:158–163
Osborn JA (1945) Demagnetizing factors of the general ellipsoid. Phys Rev 67:351–357
Ozaki M, Kratohvil S, Matijevic E (1984) Formation of monodispersed spindle-type hematite Particles. J Colloid Interface Sci 102:146–151
Pecharromán C (1994) Determinación de las Propiedades Ópticas en el infrarrojo del γ-Fe2O3. PhD Dissertation (in Spanish), UAM, Madrid
Pecharromán C, Iglesias JE (1994a) A method for the determination of IR optical constants from reflectance measurements on powdered samples. J Phys Condensed Matter 6:7125–7141
Pecharromán C, Iglesias JE (1994b) Effective dielectric properties of packed mixtures of insulator particles. Phys Rev B49:7137–7147
Pecharromán C, González Carreño T, Iglesias JE (1993) Average dielectric constant of coated spheres: Application to the IR Absorption Spectra of NiO and MgO. Appl Spectrosc 47:1203–1208
Preudhomme J (1974) Corrélation entre spectre infrarouge et cristallochimie des spinelles. Séminaires Chim État Sol 7:31–41
Serna CJ, Ocaña M, Iglesias JE (1987) Optical properties of α-Fe2O3 mycrocrystals in the infrared. J Phys C20:473–484
Shirai H, Morioka Y, Nakagawa I (1982) Infrared and Raman spectra and lattice vibrations of some oxide spinels. J Phys Soc Japan 51:592–597
Slick PI (1980) Ferromagnetic Materials. Wohlfrath EP (ed) North-Holland Publishing Company, Chapter 2
Takei H, Chiba S (1966) Vacancy ordering in epitaxially-grown single crystal of γ-Fe2O3. J Phys Soc Jap, 21:1255–1263
Turrell G (1972) Infrared and Raman Spectra of Crystals. Academic Press, London, Chapter 6
Van Oosterhout GW, Roojimans CJM (1958) A new superstructure in Gamma-Ferric Oxide. Nature 181:44
White WB, De Angelis BA (1967) Interpretation of the vibrational spectra of spinels. Spectrochimica Acta 23 A:985–995
Ziolo RF, Giannelis EP, Weinstein BA, O'Horo MP, Ganguly BN, Mehrotra V, Russell MW, Huffman DR (1992) Matrix-mediated synthesis of nanocrystalline γ-Fe2O3: A new optically transparent magnetic material Science 257:219–223
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Pecharromán, C., González-Carreño, T. & Iglesias, J.E. The infrared dielectric properties of maghemite, γ-Fe2O3, from reflectance measurement on pressed powders. Phys Chem Minerals 22, 21–29 (1995). https://doi.org/10.1007/BF00202677
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DOI: https://doi.org/10.1007/BF00202677