Dilute ferrimagnetism of ilmenites Mn3FeTiSbO9 and Mn4FeTi2SbO12

Abstract

Metastable solid solutions (SS) Mn₃FeTiSbO₉ and Mn₄FeTi₂SbO₁₂ with the ilmenite structure (space group R\(\bar 3\)) have been prepared by quenching at normal conditions. The compositions of the compounds have been justified using EDX spectroscopy and X-ray diffraction. The magnetic properties of SSs have been analyzed by comparison with ferrimagnetic ilmenite Mn₂FeSbO₆ (T_N = 269 K) as a natural mineral and ceramics obtained at high pressure and high temperature. The solid solutions have been characterized as dilute magnetic systems formed as a result of substitution of nonmagnetic cations Ti⁴⁺ for a part of Fe³⁺ and Sb⁵⁺ cations. Mn₃FeTiSbO₉ is considered as a ferromagnetic with T_N = 171 K and Mn₄FeTi₂SbO₁₂ as a magnetic with the concentration of magnetic clusters below the percolation threshold.