Structural and magnetic investigation of Fe-doped Mn3− <i>x</i> Fe <i>x</i> O4 ( <i>x</i> ≤ 0.1)

In this study, structural and magnetic properties of Fe ion-containing manganese ferrites Mn3−xFexO4 (x ≤ 0.1) have been investigated by using x-ray diffraction, superconducting quantum interference device magnetometer, and Mössbauer spectroscopy. Spin structure of Mn-rich ferrite was monitored by small-amount substitution of Fe for Mn. Mössbauer spectra showed that small amount of Fe2+ presented in the tetrahedral site. Since the Mn3+ ion in the octahedral site is Jahn–Teller active, large tetragonality was detected for x ≤ 0.075 at room temperature. For x = 0.08, sub-spectrum of Fe2+ located at the tetrahedral site gradually disappeared with increasing temperature. Inspired by this observation, the possibility of controlling the tetragonality and spin structure not only by varying temperature but also by gradually adding non-Jahn–Teller Mössbauer ion into Mn3O4 has been examined.