On the spectra of BAW resonator with ferromagnetic-ferroelectric layered structure at magnetoacoustic resonance

The theory of a composite acoustic resonator, containing layers of magnets and nonmagnetic dielectric/ferroelectric, placed in a transverse magnetic field is presented. Analytical expressions for the input electrical impedance Z_e of the piezoelectric transducer for shear acoustic waves were obtained. Numerical calculations of spectral characteristics of the resonator with ZnO as a piezoelectric layer and crystal YIG films as magnetic layers were performed. The possibility to control HBAR resonant frequency without significant reduction in quality factor is demonstrated. It is shown that for a thin ferrite film the influence of the external magnetic field on individual resonance peaks takes place. It is due to the fact that separate spin wave resonance in a thin YIG film can be adjusted by bias field so this resonance is close to a separate bulk acoustic wave resonance.