High magnetoelectric effect in laminated composites of giant magnetostrictive alloy and lead-free piezoelectric ceramic

Abstract

Magnetoelectric (ME) laminated composites with all phases environmentally friendly were prepared by sandwiching one layer of thickness-polarized (Bi[sub ½]Na[sub ½]TiO₃-(Bi[sub ½]K[sub ½]TiO₃-BaTiO₃ lead-free piezoelectric ceramic disk between two layers of thickness-magnetized Tb[sub 0.3]Dy[sub 0.7]Fe[sub 1.92] giant magnetostrictive alloy disk along the thickness direction. The composites exhibited the maximum ME voltage coefficient of 40.7 mV/Oe with a flat response in the measured frequency range of 0.1−20 kHz under a dc magnetic bias of 5 kOe. The induced ME voltage showed an extremely linear relationship to the applied ac magnetic field with amplitude varying from 3 x 10[sup −5] to 10 Oe over a broad range of dc magnetic bias of 0−5.5 kOe. The high ME effect was analyzed and found to be comparable to most major lead-based ME composites. The present study opens up possibilities for developing green ME devices.