Iron-57 and Antimony-121 Mössbauer-Effect Study of Several Spinel Antimonates

Author

Fernande Grandjean, Missouri University of Science and TechnologyFollow
Gary J. Long, Missouri University of Science and TechnologyFollow
Geoffrey E. Longworth
Brian J. Laundy

Abstract

The iron - 57 and antimony - 121 Mössbauer - effect spectra of six iron - containing antimonate spinels, of general formula M^II ₁₂Fe^II ₃Sb^V ₃O₂₄, where M^II is divalent zinc, magnesium, cobalt, and nickel, and the spinel Ni₁₀Fe₆Sb₂O₂₄ have been measured and the 4.2 K iron - 57 results used to determine the cation distribution between the tetrahedral A and the octahedral B sites. If M^II is diamagnetic zinc(II), all the iron(III) is located on the octahedral B site and the ordering temperature is ca. 1.35 K. In the orthorhombic spinel Mg₁₂Fe₃Sb₃O₂₄, two - thirds of the iron is on the tetrahedral A site and the ordering temperature is ca. 5 K. When M^II is nickel(II) and either cobalt(II) or magnesium(II), there is a distinct preference for the nickel(II) to occupy the octahedral B site and, in so doing, to displace some additional iron(III) from these sites onto the tetrahedral A sites. The presence of magnetic cobalt(II) and nickel(II) cations increases the ordering temperature to ca. 200 K in these compounds. In each case the room - temperature spectra show lines corresponding to both tetrahedral and octahedral iron(III) quadrupole - split doublets with typical hyperfine parameters. Below the ordering temperature, each compound shows at least two iron - 57 Mössbauer - effect magnetic sextets with hyperfine fields at 4.2 K of ca. 450 kOe for the tetrahedral site and ca. 530 kOe for the octahedral site. In several instances, a small distribution in the hyperfine field is observed and attributed to the distribution of the cations on the near - neighbor sites. In each compound a few area percent of a paramagnetic impurity is observed in the magnetic spectra, and the nature of this impurity is discussed. The room - temperature antimony - 121 Mössbauer spectra of these materials show an isomer shift typical of antimony(V) and no hyperfine field at the antimony nucleus. Similar results are obtained for Zn₁₂Fe₃Sb₃O₂₄ and Mg₁₂Fe₃Sb₃O₂₄ at 4.2 K. However, the compounds containing magnetic M^II dications show supertransferred hyperfine fields at the antimony, the magnitudes of which may be related to the nature and distribution of the dications.

Recommended Citation

F. Grandjean et al., "Iron-57 and Antimony-121 Mössbauer-Effect Study of Several Spinel Antimonates," Inorganic Chemistry, vol. 23, no. 13, pp. 1886 - 1895, American Chemical Society (ACS), Jun 1984.

The definitive version is available at https://doi.org/10.1021/ic00181a021

Department(s)

Chemistry

International Standard Serial Number (ISSN)

0020-1669

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 1984 American Chemical Society (ACS), All rights reserved.

Publication Date

01 Jun 1984