Observation of electric polarization reversal and magnetodielectric effect in orthochromites: A comparison between LuCrO 3 and ErCrO 3
Résumé
The presence of electric field–induced polarization reversal behavior just below Néel's antiferromagnetic ordering temperature (TN) is demonstrated in polycrystalline orthorhombic LuCrO3, which crystallizes in the centrosymmetric space group (Pbnm) at room temperature. This result on LuCrO3 is compared with ErCrO3, another orthochromite. The single phase nature and the quality of both polycrystalline samples were checked by x-ray diffraction and transmission electron microscopy (TEM). The high-resolution TEM images of LuCrO3 and ErCrO3 brought out the presence of twin boundaries. Detailed magnetic, dielectric, and polarization studies were carried out on both systems. As the presence of ferroelectric-like characteristics is found below TN in both LuCrO3 and ErCrO3, this rules out the condition for the rare earth cation to be paramagnetic for observing possible signatures of multiferroicity in this family of compounds. Also, we report a much stronger magnetodielectric effect in the case of ErCrO3 compared with LuCrO3 reflecting the different magnetism of their A-site cations.