  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.
