Effect of Ba and Zr co-substitution on dielectric and magnetoelectric properties of BiFeO3 multiferroics

TL;DR

This study investigates how co-substituting Ba and Zr into BiFeO3 affects its structural, dielectric, magnetic, and magnetoelectric properties, revealing enhanced magnetization and intrinsic coupling at room temperature.

Contribution

It is the first comprehensive analysis of Ba and Zr co-substitution effects on multiple properties of BiFeO3 multiferroics using various characterization techniques.

Findings

Unit cell volume decreases with substitution.

Dielectric anomalies become more pronounced with composition.

A crossover from antiferromagnetism to weak ferromagnetism occurs at x=y=0.1.

Abstract

We report the effect of Ba and Zr co-substitution on structural, dielectric, magnetic and magnetoelectric properties of BiFeO3 multiferroics. Polycrystalline nanoceramic samples of Bi1- xBaxFe1-yZryO3 have been synthesized by auto-combustion method. Rietveld refinement result of X-ray diffraction data indicate a contraction of unit cell volume with increase in x and y. Field emission scanning electron micrographs show densely populated grains without any voids or defects with well-defined grain boundary and decrease in grain size with increasing x and y. The result of dielectric measurement display anomalies, which are amplified and the temperature at which dielectric anomalies observed decreases with increasing composition. A cross-over from anti-ferromagnetism to weak ferromagnetism has been observed at x = y = 0.1 with enhanced magnetization as compared to pure BiFeO3. Ferroelectric properties of the sample have been studied using PE loop measurement. Magneto-dielectric and magneto impedance spectroscopy reveal the existence of intrinsic magneto-electric coupling at room temperature.