Enhanced multiferroic effect in multi-phased Eu substituted Bi–Fe–Mn perovskite oxides

Abstract

Eu substituted Bi–Fe–Mn multiferroics with a chemical formula Bi1-xEux(Fe0.8Mn0.2)O3 (x = 0.0, 0.01, 0.02, 0.03 and 0.04) were synthesized by the sol-gel auto-combustion method. Crystal structure phases of all the prepared samples were investigated by X-ray diffraction (XRD) patterns. Three different phases triclinic/anorthic (space group: P1), cubic (space group: I 2 3) and orhtorhombic (space group: Pbam) ware observed in the samples. The grain size obtained from scanning electron micrographs was found in the range of few micro-meter dimensions. The X-ray electron diffraction analysis spectrum indicates that the percentage of Bi, Eu, Fe and Mn elements are presented in approximately stoichiometric proportion. Substitution of Eu enhaces the ferromagnetic properties obtained by using vibrating sample magnetometer. The dielectric constant (ε′) and dielectric loss tangent (tanδ) measured as a function of applied frequency by using two-probe technique attains saturation state in the higher frequency regime. Impedence spectroscopy reveals the Eu-substitution dependency of the bulk relaxation in the investigated frequency range. The ferroelectric polarization electric field (P–E) curves of Bi1-xEux(Fe0.8Mn0.2)O3 measured under the electric field and at a constant frequency. The variation of magneto-electric (ME) coupling coefficient with the application of DC magnetic field were measured for all the samples.