Room temperature multiferroic properties and magnetoelectric coupling in Sm and Ni substituted Bi4−xSmxTi3−xNixO12±δ (x = 0, 0.02, 0.05, 0.07) ceramics

Abstract

Lead free multiferroic Bi4−xSmxTi3−xNixO12±δ (x = 0.02, 0.05, and 0.07) samples have been synthesized by conventional solid state route. X-ray diffraction analysis reveals single phase up to x = 0.07, and a secondary phase appears at x > 0.07. Raman spectroscopy confirms the local distortions in the crystal. Field emission scanning electron microscopy shows plate like grains. Substitution has increased the orthorhombic distortion, grain size, and hence the ferroelectric transition temperature (Tc). A significant reduction in the values of dielectric constant (ε′) and loss tangent (tan δ) has been observed with the increase of Sm and Ni ions. The increase in dc resistivity at room temperature has been found with substitution. Enhancement in the values of remnant polarization (2Pr) and magnetization (2Mr) is observed. Magnetoelectric coupling coefficient (α) values of 0.60 mV/cm/Oe are achieved in Bi4−xSmxTi3−xNixO12±δ ceramic samples. Hence, we have successfully converted the ferroelectric Bi4Ti3O12 into a multiferroic, which is a new lead free multiferroic material, can be useful for future electromagnetic devices.