An Effect of Fe3+ Ion Substitution for Cr3+ in the Octahedral Sites of FeCr2O4 Multiferroic Spinel: Mössbauer Spectroscopy Study

We present the results of a successful synthesis and investigation of polycrystalline Fe2+(Cr3+, Fe3+)2O4 powder, where 1/8 part of the Cr3+ ions in the octahedral sites is substituted by the Fe3+ ones. It is shown that under such doping, the material retains the cubic spinel structure characteristic of the parent FeCr2O4 compound. However, the values of the critical temperatures have changed. Both the orbital and magnetic orderings occur at about 120 K, and magnetic structure rearrangement associated with an onset of spiral modulation takes place at 26 K. Mössbauer studies in a wide temperature range make it possible to accurately control the content of iron ions, their valence and magnetic states, and local environment, therefore, allowing a deeper understanding of the features of the revealed transformations.