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Barium ferrite



Barium ferrite, abbreviated BaFe, is the chemical compound with the formula BaFe2O4. This and related ferrite materials are components in magnetic stripe cards. BaFe is described as Ba2+(Fe3+)2(O2-)4. The Fe3+ centers, with a high-spin d5 configuration, are ferromagnetically coupled.[1] This area of technology is usually considered to be an application of the related fields of materials science and solid state chemistry.

Additional recommended knowledge

A related family of industrially useful "hexagonal ferrites" are known, also containing barium. In contrast to the usual spinel structure, these materials feature hexagonally close-packed framework of oxides. Furthermore some the oxygen centers are replaced by Ba2+ ions. Formulas for these species include BaFe12O19, BaFe15O23, and BaFe18O27.[2] Thus, BaFe12O19 is related to Fe12O20, with the empirical formula Fe3O4, i.e. magnetite.[3]

Barium ferrites are robust ceramics that are generally stable to moisture and corrosion-resistant.[4]

References

  1. ^ Shriver, D. F.; Atkins, P. W.; Overton, T. L.; Rourke, J. P.; Weller, M. T.; Armstrong, F. A. (2006). Inorganic Chemistry. New York: W. H. Freeman. ISBN 0-7167-4878-9. 
  2. ^ Y. Goto, T. Takada (1960). "Phase Diagram of the System BaO-Fe2O3". Journal of the American Ceramic Society 43 (3): 150-153. doi:10.1111/j.1151-2916.1960.tb14330.x.
  3. ^ Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.
  4. ^ C. Okazaki, S. Mori, F. Kanamaru (1961). "Magnetic and Crystallographical Properties of Hexagonal Barium Mono-Ferrite, BaO·Fe2O3". Journal of the Physical Society of Japan 16 (3): 119-119. doi:10.1143/JPSJ.16.119.
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Barium_ferrite". A list of authors is available in Wikipedia.
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