Room temperature multiferroic behaviour and magnetoelectric coupling in Sm/Fe modified Bi4Ti3O12 ceramics synthesized by solid state reaction method

Abstract

Lead-free and single phase Bi4-xSmxTi3-xFexO12 +/-delta (0 <= x <= 0.3) ceramics were synthesized using solid state reaction method. Relaxation of distortion in TiO6 octahedron was confirmed by Raman spectroscopy analysis. The study of surface morphology by field emission scanning electron microscope (FE-SEM) reveals the growth of plate-like grains. Frequency dependent dielectric studies display the reduction of dispersion in both dielectric constant as well as loss tangent with substitution. It is observed that ferroelectric transition temperature (T-c) of bismuth titanate (BIT) decreases with increasing content of Sm3+ and Fe3+ ions. The increase in dc resistivity at room temperature has been found with substitution. A significant improvement in remnant polarization (2P(r)) and magnetization (2M(r)) has been found in the system on substitution. Magnetoelectric coupling coefficient, alpha = 0.84 mV/cm Oe is realized for x = 0.3 ceramic sample at room temperature. Our results clearly demonstrates the lead-free, multiferroic nature of Sm/Fe substituted BIT, which may find useful application in designing multiple state memory elements, data storage devices and sensors. (C) 2015 Elsevier B.V. All rights reserved