Eu-doping effects on the structural and multiferroic properties of YMn0.5Cr0.5O3

Abstract

Y1−xEuxMn0.5Cr0.5O3 (x = 0.1–1.0) oxides were synthesized in a polycrystalline form by a conventional solid-state reaction method. X-ray diffraction patterns revealed that the whole series of compounds featured a simple distorted perovskite structure with the orthorhombic space group Pbnm. With increasing Eu content, the shorter a and c axes increased, while the longest b axis changed little. The ferrimagnetic transition temperature TN increased gradually to x = 0.8 before declining with a further increase in x. A clear correlation between TN and the negative molecular field coefficient within the Cr3+ sublattice indicated that an antiferromagnetic exchange interaction between the Cr3+ cations plays a dominant role in the magnetic ordering. By reversing the sign of the poling field, the occurrence of electric polarization reversal at temperatures around TN implied a possible multiferroic state in the samples. From the dielectric point of view, the disappearance of the dielectric constant anomaly at TN might be related to the high AC conductivity of the samples, which is a common feature of orthochromites.