Journal of Nanoparticle Research

, Volume 11, Issue 5, pp 1145–1158

Structure of manganese zinc ferrite spinel nanoparticles prepared with co-precipitation in reversed microemulsions

Authors

    • Jožef Stefan Institute
  • Alojz Kodre
    • Jožef Stefan Institute
    • Faculty of Mathematics and PhysicsUniversity of Ljubljana
  • Iztok Arčon
    • Jožef Stefan Institute
    • University of Nova Gorica
  • Miha Drofenik
    • Jožef Stefan Institute
    • Faculty of Chemistry and Chemical EngineeringUniversity of Maribor
Research Paper

DOI: 10.1007/s11051-008-9510-0

Cite this article as:
Makovec, D., Kodre, A., Arčon, I. et al. J Nanopart Res (2009) 11: 1145. doi:10.1007/s11051-008-9510-0

Abstract

The structure of Mn0.5Zn0.5Fe2O4 spinel ferrite nanoparticles is studied as a function of their size and the experimental conditions of their synthesis using X-ray absorption spectroscopy. The nanoparticles of different sizes down to approximately 2 nm and with a narrow size distribution were synthesized using co-precipitation in reverse microemulsions. Simultaneous refinement of the X-ray absorption fine structure (EXAFS) of three constituting metals shows a migration of Mn and Zn ions to the octahedral site of the spinel lattice compensated by the corresponding migration of the Fe ions. To a smaller extent, Mn ions switch the occupation site already in bulk and in larger nanoparticles, while a sporadic migration of Zn is detected only in the nanoparticles with sizes below approximately 5 nm. X-ray absorption near edge structure (XANES) reveals considerable variations in the position of the Mn K edge, suggesting the average Mn valence in the nanoparticles to be higher than 3+. Annealing at 500 °C relaxes the structure of as-synthesized nanoparticles toward the structure of the ceramic bulk standard.

Keywords

Nanoparticles Spinel ferrites Structure EXAFS Magnetic properties Nanomaterial

Supplementary material

11051_2008_9510_MOESM1_ESM.doc (44 kb)
(DOC 43 kb)
11051_2008_9510_MOESM2_ESM.tif (533 kb)
EXAFS k-space spectra of Fe K edge. (TIFF 532 kb)
11051_2008_9510_MOESM3_ESM.tif (500 kb)
EXAFS k-space spectra of Zn K edge. (TIFF 499 kb)
11051_2008_9510_MOESM4_ESM.tif (548 kb)
EXAFS k-space spectra of Mn K edge. (TIFF 547 kb)

Copyright information

© Springer Science+Business Media B.V. 2008