Effect of Fe substitution on multiferroic hexagonal YMnO3

Polycrystalline YMn1−xFexO3 (x=0.02–0.20) powders were synthesized by means of modified citrate method. Powder X-ray diffraction gives evidence that all the samples are single phase and exhibit hexagonal structure with P63cm space group as observed for YMnO3. The solubility limit of Fe was determined as about 6 wt.%. Cell parameter values were found to increase with Fe content, since Fe3+ and Mn3+ have the same ionic radii. This can be attributed to the increase of the tilting of MnO5 bipyramid and the buckling of Y atoms. In addition, 57Fe Mössbauer spectrometry provides evidence of two Fe3+ sites attributed to two different nearest atomic neighbours. Magnetic properties reveal a paramagnetic-to-antiferromagnetic transition, a possible increase of the magnetic anisotropy, and a competition between ferromagnetic and antiferromagnetic interactions.

Research highlights
► The increase of the tilting of MnO5 bipyramid and the buckling of Y atoms leads to the increase of cell parameter in YMn1-xFexO3.
► 57Fe Mössbauer spectrometry provides evidence of two Fe3+ sites.