Effect of Barium Substitution on Ferroelectric and Magnetic Properties of Bismuth Ferrite

Abstract

We successfully synthesized Bi <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-x</sub> Ba <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> FeO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> = 0.0, 0.20, 0.25) replacing Bi by Ba using a chemical synthesis route. The phase and crystal structure of the samples were studied by X-ray diffraction (XRD). Peaks in the XRD shifted toward lower θ value with the increase in Ba concentration due to the increase in the unit cell size. Detail thermal behavior was performed by differential scanning calorimetry and differential thermal analysis (DTA) to investigate the change in magnetic and ferroelectric transition temperature, respectively, due to Ba substitution. Magnetic, dielectric, and magnetoelectric properties of the samples were also studied in detail. Antiferromagnetic bismuth ferrite was converted to ferromagnetic materials at room temperature on incorporating Ba in the crystal structure. Polarization versus electric field (P-E loop) and dielectric constant were also found to change significantly in the presence of a magnetic field in the aforementioned samples. Appreciable magnetodielectric effect [ε <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</sub> (H)-ε <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</sub> (0)]/ε <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</sub> (0) also indicated effective magnetoelectric coupling within the materials.