Synthesis of (1-x) [Bi0.9Eu0.1FeO3] + x [Ni0.6Zn0.4Fe2O3] Nanostructured Multiferroic Composites and Study of its Structural, Magnetic and Electrical Properties

Abstract

Multiferroic Composites with different mass ratio of Europium doped Bismuth Ferrite (BEFO) and Nickel Zinc Ferrite (NZF) with general formula (1-x) [Bi0.9Eu0.1FeO3] + x [Ni0.6Zn0.4Fe2O4] for various x values (x=0, 0.1, 0.3, 0.5, 0.7 and 1) have been prepared by the conventional solid-state reaction method aided with different dispersion techniques like magnetic stirring, power ultrasonification and centrifugation. Crystallinity and structure of the samples were investigated by powder X-ray diffraction and distorted rhombohedral perovskite BEFO and cubic NZF has been observed for x = 0.0 and x = 1.0. Mixed perovskite-spinel structure has been observed for the composites which prove that in the composite BEFO and NZF phases coexist together with no chemical reaction. The formation of nano is observed through FESEM micrographs and the compositional purity of the prepared samples has been confirmed by Energy dispersive x-ray Spectra (EDX). To understand the temperature dependent grain growth of the samples, all the samples were heated at 3000 C, 4500 C, 6000 C, 7500 C and 8500 C and the average grain size has been observed in between (65 ~ 75) nm, (65 ~ 70) nm, (55 ~ 70) nm, (350 ~ 400) nm and (750 ~ 800) nm respectively. The ferromagnetic hysteresis behavior of the samples have been obtained through vibrating sample magnetometer (VSM) and the magnetic properties such as saturation magnetization (Ms), remanent magnetization (Mr), coercive field (Hc), molecular magnetic moment (μB) and magnetic anisotropy constant are calculated from it. It has been observed that Ms has increased with increasing NZF content. The complex permeability (μ) of the prepared samples have been measured and a fairly constant initial permeability (μ') has been observed over a wide range of frequency (~108 Hz) region. Dielectric properties and AC conductivity of the samples have been studied in a wide range of frequencies from 1Hz to 100MHz at room temperature by impedance analyzer and found that x = 0.1 shows the maximum dielectric constant. Dielectric dispersion has been observed at lower frequency (< 105 Hz) and is attributed to the interfacial polarization. The complex impedance spectroscopy is used to correlate between the electrical properties of the studied samples with their microstructure. The optimum composition is observed for x = 0.1 which possess the highest frequency dependent dielectric constant and permeability with lower dielectric and magnetic loss.