The first observation of microwave magnetoelectric (ME) interactions through ferromagnetic resonance (FMR) in bilayers of single crystal ferromagnetic-piezoelectric oxides and a theoretical model for the effect are presented. An electric field E produces a mechanical deformation in the piezoelectric phase, resulting in a shift δH E in the resonance field for the ferromagnet. The strength of ME coupling is obtained from data on δH E vs E. Studies were performed at 9.3 GHz on bilayers of (111) yttrium iron garnet (YIG) films and (001) lead magnesium niobatelead titanate (PMN-PT). The samples were positioned outside a TE 102 -reflection type cavity. Resonance profiles were obtained for E = 0-8 kV/cm for both in-plane and out-of-plane magnetic fields H. Important results are as follows. (i) The ME coupling in the bilayers is an order of magnitude stronger than in polycrystalline composites and is in the range 1-5.4 Oe cm/kOe, depending on the YIG film thickness. (ii) The coupling strength is dependent on the magnetic field orientation and is higher for out-of-plane H than for in-plane H. (iii) Estimated ME constant and its dependence on volume ratio for the two phases are in good agreement with the data.

No abstract

No abstract

Millimeter-wave magnetoelectric interactions have been studied through electric field effects on magnetic excitations in bilayers of single crystal barium ferrite and lead zirconate titanate ͑PZT͒. An electric field E produces a mechanical deformation in PZT, resulting in a shift ␦f in the frequency for electromagnetic modes in the ferrite. Reflected power versus frequency profiles at 40-55 GHz for a series of bias magnetic field and E =0-10 kV/cm along the c axis of the ferrite showed an increase in ␦f to a maximum of 8 MHz. Theoretical estimates of ␦f are in agreement with the data.

An electric field tunable yttrium iron garnet (YIG)-lead zirconate titanate (PZT) phase shifter based on ferromagnetic resonance (FMR) is designed and characterized. The electric field control of the phase shift δφ arises through magnetoelectric interactions. The piezoelectric deformation in PZT in an electric field E leads to a shift in the FMR frequency in YIG and a phase shift. For E=5–8kV∕cm applied across PZT, δφ=90°–180° and an insertion loss of 1.5–4dB are obtained. Theoretical estimates of δφ are in excellent agreement with the data.