Magnetoelectric coupling studies on (x) (0.5BZT-0.5BCT) – (100-x) NiFe < inf > 2 < /inf > O < inf > 4 < /inf > [x=90−70 wt%] particulate composite

Abstract

In this article, the effect of composition on magnetoelectric properties of lead-free (x) [0.5BZT – 0.5BCT] – (100-x) NiFe2O4 (x=90, 80, 70 wt%) particulate composites synthesized by sol-gel method was studied. Presence of ferroelectric and ferromagnetic phases in the composites was confirmed using x-ray diffraction technique. The microstructure of the composites displayed uniform grains distribution and dispersion of NFO phase in BCZT matrix. The co-existence of ferroelectric and magnetic orderings at room temperature was confirmed by measuring the P-E and M-H loops respectively, of the particulate composites. Frequency dependence of admittance measurements exhibited high electro-mechanical coupling coefficient (kp) in the range of 0.41 to 0.37. The magneto-electric (ME) properties of the composites were studied both in longitudinal (αE,33) and transverse (αE,31) modes at low frequency of 1 kHz under external bias field (Hdc). High strain mediated ME coupling responses, αE,31=13.3 mV/cm Oe, 8 mV/cm Oe and 4.3 mV/cm Oe were recorded for samples with x=80, 90, and 70 wt% BCZT respectively.