Enhanced multiferroic characteristics in hexagonal ScMn1−xFexO3 ceramics.

In the present study, enhanced antiferromagnetic characteristics and room temperature magnetoelectric coupling are achieved by Fe-substitution for Mn in h-ScMnO₃. The antiferromagnetic Néel temperature (T_N) increases from 131 K for ScMnO₃ up to 140 K for ScMn_0.8Fe_0.2O₃. Electric field controlled magnetism is confirmed for ScMn_0.8Fe_0.2O₃ at room temperature, combining with the short-range magnetic spin ordering. The Rietveld structural refinement and selected area electron diffraction confirm the noncentrosymmetric P6₃cm structure for the present ceramics. The ferroelectric domain walls at the atomic scale are determined by the aberration-corrected high-angle annular dark-field scanning transmission electron microscopy; meanwhile, the spontaneous polarization of 5.6 μC/cm² is determined. The noticeable magnetoelectric coefficient α_ME ∼ 0.78 mV/cm Oe (measured under a magnetic field up to 3000 Oe) is obtained in ScMn_0.8Fe_0.2O₃, which is quite stable with the applied magnetic field, reflecting coupling of the short-range spin ordering with the ferroelectric ordering. The enhanced antiferromagnetic behaviors are discussed with the effect of Fe-substitution, which reduce the magnetic frustration and enhance the exchange interaction. [ABSTRACT FROM AUTHOR]