Low frequency and microwave magnetoelectric effects in thick film heterostructures of lithium zinc ferrite and lead zirconate titanate

Magnetoelectric (ME) coupling at low frequencies and at x-band have been investigated in layered samples containing zinc substituted lithium ferrite and lead zirconate titanate (PZT). Multilayers of Li0.5−x/2ZnxFe2.5−x/2O4 (LZFO) (x=0–0.4) and PZT were prepared by lamination and sintering of thick films. At low frequencies (10–1000 Hz), the ME voltage coefficient for transverse fields is higher than for longitudinal fields. With Zn substitution in the ferrite, transverse coupling increases to a maximum for x=0.3 and then decreases for higher x. Analysis based on our model for a bilayer implies an efficient magneto-mechanical coupling with Zn substitution, resulting in strong ME interactions. Microwave ME coupling is studied through measurements of shift in the ferromagnetic resonance field due to an applied electric field. Estimated ME constants from such data are in agreement with our model for a ferrite–PZT bilayer.