Enhanced magnetoelectric response from lead-free (Ba < inf > 0.85 < /inf > Ca < inf > 0.15 < /inf > )(Zr < inf > 0.1 < /inf > Ti < inf > 0.9 < /inf > )O < inf > 3 < /inf > – CoFe < inf > 2 < /inf > O < inf > 4 < /inf > laminate and particulate composites

Abstract

Lead free multiferroic composite (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 - CoFe2O4 was prepared in two different connectivity schemes, particulate and laminates and their magnetoelectric properties have been investigated in this study. Lead free piezoelectric (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 (BCZT) and ferrimagnetic CoFe2O4 (CFO) phases were synthesized by sol-gel and combustion techniques respectively. Particulate composite was prepared by mechanical mixing of BCZT and CFO phases in equal weight fraction. The laminate structures (bilayer and trilayer) was developed by bonding BCZT with CFO layers by epoxy bonding. High piezoelectric coefficients, d33 ~ 630 pC/N, g33 ~11 mV m/N, and magnetostricition ~183 ppm were obtained for the laminate composite. Magnetoelectric measurements revealed a large ME response for the trilayer laminate composite especially at high frequency, where the electro-mechanical resonance appears for the composite. A high magnetoelectric coefficient (αME) ~803 mV cm−1 Oe−1 was obtained for the trilayer laminate composite which was 8 times higher than that of the particulate composite, αME ~ 104 mV cm−1 Oe−1. Bilayer laminate showed a maximum (αME) coefficient of ~ 615 mV cm−1 Oe−1. The magnetoelectric behavior of all the three composites is discussed and compared in this study.