Evidence of Tetrahedrally Coordinated Nickel Cations in Nanostructured NiFe₂O₄.

Nanostructured nickel ferrite (NiFe₂O₄) is prepared via high-energy ball milling of the bulk counterpart at ambient temperature. The structure of the as-prepared nanoferrite is characterized by Raman spectroscopy and 57 Fe Mössbauer spectroscopy. Due to the ability of these spectroscopic techniques to probe the local environment of ions, valuable complementary insight into the nature of the local structural disorder of nanosized NiFe₂O₄ is provided. For the first time, evidence is given of the tetrahedrally coordinated nickel cations in the nanomaterial.