A comprehensive investigation on structural, microstructural, optical, electrical, magnetic, and magnetoelectric (ME) properties of the single phase Bi4LaFeTi3−2x(WyCo2y)xO15 (0.00 ≤ x ≤ 0.15, y = 1.0) Aurivillius ceramics has been presented here. The preliminary x-ray diffraction and Raman spectroscopic studies reveal that a layered-structure perovskite Aurivillius phase of orthorhombic space group A21am. Furthermore, the surface morphology study provides a plate-like to spherical-like granules with increasing the dopant concentrations. The ferroelectric response prevails a slim P–E loop for pristine sample, whereas it provides the highest polarization (Ps) values of 7.21 and 13.25 μC/cm2 for x = 0.10 and 0.15 concentrations, respectively. At low temperature, magnetic measurements provide a weak antiferromagnetic ordering of pristine sample, whereas a strong FM (ferromagnetic) ordering of doped ceramics is attained. The observed strong FM behavior of the Aurivillius phase is attributed to either double exchange interactions between neighboring Fe3+–O–Fe3+, Co3+–O–Co3+, and Fe3+–O–Co3+ ions or antisymmetric Dzyaloshinskii–Moriya interactions for spin canting of adjacent sub-lattices via Co3+/2+–O–Co3+/2+, Fe3+–O–Fe3+, and Co3+/2+–O–Fe3+ ions. The temperature dependent dielectric broad-band spectroscopic study enlightened a dielectric relaxation. This is due to cationic disordering through the generation of oxygen vacancies, which yields a conduction mechanism at high temperature regions. Furthermore, a complex modulus spectroscopic technique is also adopted to investigate the dielectric relaxation at high temperature regimes. The observed magnetic ferroelectric polarization responses and magnitudes of ME coupling coefficients provided that this material could be useful for future magnetoelectric sensors.

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The present work reports the analysis of temperature‐dependent electrical and conductivity studies on Ca2+ doped BiFeO3 multiferroic ceramics in the temperature range of 300–600 K. The effect of Ca2+ doping on the impedance and modulus behavior of BiFeO3 lattice is discussed. The observed changes as a function of increasing Ca2+ concentration have been explained using the change in crystal unit cell. It is also shown that the microstructure changes significantly as a function of Ca2+ concentration. The grain and grain boundary effects in determining the impedance behavior is also reported in the paper.

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