Enhance magnetoelectric coupling in xLi_0.1Ni_0.2Mn_0.6Fe_2.1O₄–(1 − x)BiFeO₃ multiferroic composites

Abstract

Lead-free multiferroic composites of xLi_0.1Ni_0.2Mn_0.6Fe_2.1O₄ (LNMFO)–(1 − x)BiFeO₃ (BFO) were prepared. Multiferroic properties of LNMFO–BFO were analyzed. The compositions are a combination of ferrite and perovskite phases verified by the measurement of X-ray diffraction. FESEM image analyzed the surface morphology of the compositions. The EDX Spectroscopy performed quantitative elemental of the compositions. The $\mu_{i}^{\prime }$ increases in the samples with ferrite concentration. Dielectric properties were analyzed with frequency. The change in $\varepsilon^{\prime }$ with frequency displays dielectric dispersion in the low frequency zone because of interfacial polarization of Maxwell–Wagner type resulting from the two phase interface. Frequency autonomous behavior of the $\varepsilon^{\prime }$ is seen in the higher frequency region as electric dipoles can not follow the rapid change in the alternating electrical field. The $\varepsilon^{\prime }$ is reduced with ferrite concentration. Dielectric loss peaks occur when the electrons hopping frequency is almost equal to the applied field frequency. The $\sigma_{AC}$ of the samples follows the power law of Jonscher and increases with frequency, indicating that there is conduction of small polaron hopping. Impedance spectroscopy studies recommend that the grain and grain boundary perform to the conduction phenomena. Magnetization was measured to study the recompose of the ferrite phase with the magnetic field. Both $M_{s}$ and $M_{r}$ have been increased with ferrite content. The magnetoelectric voltage coefficient is reduced with ferrite concentration. The maximum value of the magnetoelectric voltage coefficient is quite high, up to ~ 98 × 10³ Vm⁻¹ T⁻¹ for the composite 0.1LNMFO–0.9BFO.