Low-frequency resonant magnetoelectric effects in a planar heterostructure of ferromagnetic yttrium iron garnet film and piezoelectric quartz

Abstract

Low-frequency resonant magnetoelectric (ME) effects in a planar heterostructure containing a 50 μm thick single-crystal film of yttrium iron garnet (YIG) and a crystalline quartz platelet were studied. The ME effects in the mechanically coupled composite arise due to a combination of magnetostriction of the YIG film and the piezoelectric effect in quartz. The effects manifest as mutual transformation of ac magnetic and electric fields. When the layered composite was excited by an ac magnetic field (direct ME effect) at a planar acoustic resonance frequency of 128 kHz, the ME field conversion coefficient was 8.8 V/(Oe∙cm). When excited by an ac electric field (converse effect), the ME conversion coefficient was 0.32 G/(V/cm). Nonlinear ME effects caused by the nonlinear magnetostriction of the YIG film were observed as frequency doubling upon excitation of the direct ME effect by a magnetic field at a frequency equal to half the resonant frequency, as well as at the converse ME effect upon excitation by an electric field at the frequency of the resonance of the structure. In spite of weak magnetostriction for YIG, the resonant ME effects in the YIG-quartz composite are comparable in magnitude to the effects in composites with high magnetostriction materials, show high quality factor of Q ∼ 2200 and are observed in weak magnetic fields H ∼ 0–60 Oe. These results demonstrate the potential for YIG film-quartz composites application in electronic devices.