Enhanced multiferroic properties in Ba and Sm co-doped BiFeO 3 ceramics

The role of co-doping with Ba and Sm in Bi and Fe sites of BiFeO 3 (BFO), respectively, on the structural and multiferroic properties has been studied in this investigation. Multiferroic ceramics Bi 0 . 85 Ba 0 . 15 Fe 1− x Sm x O 3 (BBFSO) with x = 0, 0.02, 0.05, and 0.07 have been synthesized by using the standard solid-state reaction method. The Structural depiction and surface morphology are accomplished by X-ray diffraction (XRD) and Scanning Electron Microscope (SEM), respectively. Analysis of the XRD pattern reveals that the structural phase is found pseudo-cubic with the substitution of Ba and Sm for all the samples. Microstructural investigation shows that the samples possess fine crystalline structure and the estimated grain size decreases with the increase in Sm content. The electromagnetic properties such as complex initial permeability, relative quality factor, dielectric constant, dielectric loss, and ac conductivity have been measured by Wayne Kerr Impedance Analyzer. It is found that co-doped samples have improved dielectric property. The sample having 2% Sm exhibits the highest dielectric constant and lowest loss in the dispersive region. Enhanced electric polarization is found for co-doped samples, which might be due to the reduction in leakage current. From impedance spectroscopy analysis, it is observed that only grain boundary is responsible for the conduction process and the electric modulus confirms the existence of electronic relaxation. The real part of initial permeability and relative quality factor increase significantly with Sm doping. The magnetic hysteresis loops confirm that Sm doping notably increases the coercivity of the Bi 0 . 85 Ba 0 . 15 FeO 3 ceramics. The coexistence of ferroelectricity and ferromagnetism in BBFSO as is evident from the P–E and M–H loops can be used for fabricating magnetoelectric devices.