Magnetoelectric Interactions in Layered Composites of Piezoelectric Quartz and Magnetostrictive Alloys

Mechanical strain mediated magnetoelectric effects are studied in bilayers and trilayers of piezoelectric quartz and magnetostrictive permendur (P), an alloy of Fe-Co-V. It is shown that the magneto-electric voltage coefficient (MEVC), proportional to the ratio of the piezoelectric coupling coefficient to the permittivity, is higher in quart-based composites than for traditional ferroelectrics based ME composites. In bilayers of X-cut single crystal quartz and permendur, the MEVC varies from 1.5 V/cm Oe at 20 Hz to ~ 185 V/cm Oe at bending resonance or electromechanical resonance corresponding to longitudinal acoustic modes. In symmetric quartz-P trilayers, the MEVC ~ 4.8 V/cm Oe at 20 Hz and ~ 175 V/cm Oe at longitudinal acoustic resonance. A model for low-frequency and resonance ME effects is provided for theoretical estimates of MEVC and calculated MEVC are in general agreement with measured values. Magneto-electric composites with quartz have the desired characteristics such as the absence of ferroelectric hysteresis and pyroelectric losses and could potentially replace ferroelectrics in composite-based magnetic sensors, transducers and high frequency devices.