Structure of nanocrystalline MgFe₂O₄ from X-ray diffraction, Rietveld and atomic pair distribution function analysis

The three-dimensional structure of nanocrystalline magnesium ferrite, MgFe₂O₄, prepared by ball milling, has been determined using synchrotron radiation powder diffraction and employing both Rietveld and atomic pair distribution function (PDF) analysis. The nanocrystalline ferrite exhibits a very limited structural coherence length and a high degree of structural disorder. Nevertheless, the nanoferrite possesses a very well defined local atomic ordering that may be described in terms of a spinel-type structure with Mg²⁺ and Fe³⁺ ions almost randomly distributed over its tetrahedral and octahedral sites. The new structural information helps explain the material's unusual magnetic properties.