Enhanced magnetoelectric coupling in Bi0.95Mn0.05FeO3–Ni0.5Zn0.5Fe2O4 nanocomposites for spintronic applications

Abstract

Multiferroic nanocomposites with the chemical formula, (x).Bi0.95Mn0.05FeO3-(1-x). Ni0.5Zn0.5Fe2O4, (where x = 0.2, 0.4, 0.5, 0.6, and 0.8) have been synthesized using sol–gel autocombustion and conventional solid-state reaction methods. Resistivity and impedance measurements were taken in order to understand the properties of the conductivity of the samples. Multiple hopping mechanisms were evident from the studies of impedance analysis with the traces of different trends from Nyquist plots. Magnetoelectric (ME) coupling coefficient (αME) studies were taken in order to understand the possible coupling in the synthesized composites. The composites exhibit different values for αME, and it was observed to be varying systematically in accordance with the mixing ratios of the individual constituent phases. Interestingly, the composite with equal ratio (x = 0.5) of both the individual phases shows enhanced value for αME along longitudinal and transverse modes. The observed typical values of αME along the longitudinal and transverse modes are 28.083 mV/cm. Oe and 27.098 mV/cm. Oe, respectively. The possible reasons for the improvement in the coupling factor are well discussed and are attributed to the charge balance along with the structural inhomogeneities prevailed during the formation of the composite. In addition, the observed difference in magnitudes of αME along the longitudinal and transverse modes are also examined and presented in this paper. Improved structural, resistive, impedance and magnetoelectric coupling studies suggest that these composites are well suitable for the applications of spintronic-based devices.