Effect of Fe substitution on multiferroic hexagonal YMnO3

Polycrystalline YMn(1-x)FexO(3) (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 P6(3)cm 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, Fe-57 Mossbauer 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. (C) 2010 Elsevier B.V. All rights reserved.