Comparison of the cation inversion parameter of the nanoscale milled spinel ferrites with that of the quenched bulk materials

The high-energy milling process is known to induce numerous changes in materials. In this contribution, it is pointed out that the milling of ferrimagnetic oxides leads to an extensive structural disordering such as non-equilibrium distribution of cations over the two non-equivalent cation sublattices provided by the spinel structure. The cation inversion parameter of the nanoscale milled spinel ferrites is compared with that of the bulk materials quenched from high temperatures. The degrees of inversion of 0.73 and 0.41, characterising the mechanically-induced disorder in nanosized MgFe2O4 and ZnFe2O4, respectively, correspond to the bulk ferrites quenched from about 1300 and 1700 K, respectively.