Microwave and MM-wave magnetoelectric interactions in ferrite-ferroelectric bilayers

Measurements of the strength of magnetoelectric (ME) interactions at microwave and millimeterwave frequencies have been carried out on layered ferrite-piezoelectric oxides. An electric field E applied to the composite produces a mechanical deformation, resulting in a field shift δHE or a frequency shift δfE in the resonance. A stripline structure or a cavity resonator was used. The strength of ME coupling is obtained from data on δHE or δfE vs. E. Studies were performed at 1–110 GHz on bilayers of single crystal nickel zinc ferrite or hexagonal ferrites and single crystal lead magnesium niobate-lead titanate, lead zinc niobate-lead titanate or polycrystalline lead zirconium titanate. The coupling strength has been found to be dependent on the nature of piezoelectric phase, magnetic field orientation and volume for both phases. The ME coupling strength is on the order of 1–2 Oe cm/kV (or 3–6 MHzcm/kV) and is an order of magnitude stronger than in polycrystalline ferrite-piezoelectric bilayers. The high frequency ME effect is of importance for dual electric and magnetic field tunable ferrite-piezoelectric devices. PACS. 75.80.+q Magnetomechanical and magnetoelectric effects, magnetostriction – 76.50.+g Ferromagnetic, antiferromagnetic, and ferrimagnetic resonances; spin-wave resonance – 77.65.j Piezoelectricity and electromechanical effects 77.84.-s Dielectric, piezoelectric, ferroelectric, and antiferroelectric materials