HFI / NQI 2010, p. 413-417
DOI: 10.1007/978-94-007-1269-0_66
Springer Verlag, Hyperfine Interactions, 1-3(198), p. 67-71
DOI: 10.1007/s10751-010-0243-y
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The evolution of nanocrystalline n-MgFe2O4 by high-energy milling a mixture of MgO and alpha-Fe2O3 for periods of between 0 h and 12 h has been investigated by neutron diffraction in addition to previous Mossbauer, XRD and HRTEM measurements. Complete transformation of the milled products to n-MgFe2O4 only occurs on milling to similar to 8 h even though the average particle size decreases to <similar to 10 nm after milling for 2 h. The applied field Mossbauer 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 similar to 7(1) nm and similar to 0.7(1) nm, respectively, in support of the Mossbauer core-shell model.