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

Magnetoelectric (ME) laminated composites with all phases environmentally friendly were prepared by sandwiching one layer of thickness-polarized (Bi1/2Na1/2)TiO3-(Bi1/2K1/2)TiO3-BaTiO3 lead-free piezoelectric ceramic disk between two layers of thickness-magnetized Tb0.3Dy0.7Fe1.92 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 3x10(-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. (c) 2007 American Institute of Physics.