Giant magnetoelectric effects in layered composites of nickel zinc ferrite and lead zirconate titanate

A 40-fold increase in the strength of magnetoelectric (ME) coupling is reported in layered samples of nickel ferrite (NFO)–lead zirconate titanate (PZT) compared to bulk composites. In bulk samples, the transverse and longitudinal couplings are weak and are of equal magnitude. The ME coupling strengthens by an order of magnitude when high-resistivity modified-NFO is used in the composite. A further enhancement of ME interactions is accomplished in bilayer and multilayer structures of Ni1−xZnxFe2O4(x=0–0.5)–PZT. The coupling is dependent on Zn substitution, with x=0.2 showing the strongest ME interaction. These observations are in good agreement with theory.