Enhancing the Ferroelectric Coupling of Multifunctional Spinel–Perovskite Composite

Multifunctional composites of spinel and perovskite of the general formula ( x )(Mn 0.7 Cu 0.3 Fe 2 O 4 ) + (1 − x )(La 0.90 Bi 0.10 FeO 3 ), were prepared using the auto combustion sol–gel technique. We studied the dielectric behavior of the composites and their effect on the multiferroic property of the pristine perovskites. We further characterized the composite with an ac conductivity measurement; two regions of conductivity appears in all different composite concentrations. The microstructure of the composite has also been investigated using a high-resolution transmission electron microscope. The results of the composite’s dielectric behavior and the ac conductivity shows that the electric polarization is enhanced due to the built up electric field in the grain boundaries, the built-up electric field adds additional electric polarization that increases the multiferroic coupling in the perovskite.