Is the magnetoelectric coupling in stickup bilayers linear?

The magnetoelectric (ME) characterization of stickup bilayers Ni0.8Zn0.2Fe2O3-Pb(Zr, Ti)O-3 and trilayers of Ni0.8Zn0.2Fe2O3-Pb(Zr, Ti)O-3-Ni0.8Zn0.2Fe2O3 are discussed. The ME interactions in the trilayers were found much stronger than that of bilayers prepared with the same technique. The maximum transverse ME voltage coefficient of trilayer can reach 430 (mV/cm Oe) under a magnetic field H=215 Oe. This value is much closer to the theoretical estimate for the ME coupling for bilayers. The frequency dependence of alpha(E) also reveals the difference of the elastic and magnetoelectric coupling between the bilayers and trilayers. Analysis suggests that a more approach linear response of the pezioelectric layer to the magnetostriction of the ferrite may be responsible for the significant enhanced ME effect in the trilayers. (c) 2007 American Institute of Physics.