Mechanosynthesis of nanocrystalline MgFe2O4-neutron diffraction and Mossbauer spectroscopy

Authors

V. Sepelak, Karlsruhe Institute of Technology
I. Bergmann, Volkswagen AG
A. Feldhoff, University Hannover
F. Litterst, Braunschweig University of Technology
K. Becker, Braunschweig University of Technology
John Cadogan, University of Manitoba, Winnipeg
M. Hofmann, Technische Universität München
M. Hoelzel, Technische Universität München
Jianli Wang, University of New South WalesFollow
Maxim Avdeev, Australian Nuclear Science and Technology Organisation (ANSTO)
Stewart Campbell, The University of New South Wales

RIS ID

40010

Publication Details

Sepelak, V., Bergmann, I., Feldhoff, A., Litterst, F. J., Becker, K. D., Cadogan, J. M., Hofmann, M., Hoelzel, M., Wang, J., Avdeev, M. & Campbell, S. J. (2010). Mechanosynthesis of nanocrystalline MgFe₂O₄-neutron diffraction and Mossbauer spectroscopy. Hyperfine Interactions, 198 (1-3), 67-71.

Abstract

The evolution of nanocrystalline n-MgFe₂O₄ by high-energy milling a mixture of MgO and α-Fe₂O₃ for periods of between 0 h and 12 h has been investigated by neutron diffraction in addition to previous Mössbauer, XRD and HRTEM measurements. Complete transformation of the milled products to n-MgFe₂O₄ only occurs on milling to ∼8 h even though the average particle size decreases to < ∼10 nm after milling for 2 h. The applied field Mössbauer spectra of n-MgFe₂O₄ can be well described by two subspectra representing core and shell regions with different cation distributions and spin canting angles. The neutron pattern of nanocrystalline MgFe₂O₄ is described well by two components comprising nanoparticles of core and shell dimensions ∼7(1) nm and ∼0.7(1) nm, respectively, in support of the Mössbauer core-shell model.