Structural and magnetoelectric properties of MFe2O4-PZT (M = Ni, Co) and Lax(Ca, Sr)1-xMnO3-PZT multilayer composites

Thick-film layered magnetoelectric composites consisting of ferromagnetic and ferroelectric phases have been synthesized with nickel ferrite (NFO), cobalt ferrite, La0.7Sr0.3MnO3 (LSMO), or La0.7Ca0.3MnO3 (LCMO) and lead zirconate titanate (PZT). Structural, magnetic, and ferromagnetic resonance characterization shows evidence for defect-free ferrites, but deterioration of manganite parameters. The resistivity and dielectric constants are smaller than expected values. The magnetoelectric effect (ME) is stronger in ferrite-PZT than in manganite-PZT. The ME voltage coefficient alpha(E) at room temperature is the highest in NFO-PZT and the smallest for LCMO-PZT. The transverse ME effect is an order of magnitude stronger than the longitudinal effect. The magnitude of alpha(E) correlates well with magnetic permeability for the ferrites.