Investigation on the effect of ferrite content on the multiferroic properties of (1-x) Ba0.95Sr0.05TiO3 – (x) Ni0.7Zn0.2Co0.1Fe2O4 ceramic composite

Abstract

(1-x) Ba0.95Sr0.05TiO3 – (x) Ni0.7Zn0.2Co0.1Fe2O4 magnetoelectric composites are synthesized by the standard solid state reaction method and are investigated in detail. X-ray diffraction (XRD) analysis confirms the successful formation of the composites. The results of scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) reveal that NZCF phase is well dispersed in the BST matrix and has larger average grain size. The dielectric constant variation with frequency demonstrates dispersion in the low frequency region which may be ascribed to the Maxwell–Wagner interfacial polarization. Besides, the dielectric constant vs. Temperature plots of the composites exhibit ferroelectric to paraelectric phase transition, which is dependent on the NZCF content. A sharp transition peak is observed for low ferrite content, whereas for higher ferrite content, it seems to be suppressed. The maximum value of the piezoelectric coefficient (d33) obtained for the composites is 25 pC/N. With increasing NZCF content in the composites, the ferromagnetic properties get stronger while, ferroelectric behavior is gradually weakens. The observed behavior of magnetoelectric coefficient (αE) is explained in terms of variation of the resistivity of the composites and the ferrite concentration and maximum αE achieved is 2.58 mV/cm Oe for the composite with 70% BST + 30% NZCF.