  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.
