A permendur-piezoelectric multiferroic composite for low-noise ultrasensitive magnetic field sensors

Low-frequency and resonance magnetoelectric (ME) effects have been studied for a trilayer of permendur (alloy of Fe-Co-V) and lead zirconate titanate (PZT). The high permeability and high magnetostriction for permendur, key ingredients for magnetic field confinement, and ME response result in ME voltage coefficient of 23 V/cm Oe at low-frequency and 250 V/cm Oe at electromechanical resonance (EMR) for a sample with PZT fibers and inter-digital-electrodes. Theoretical ME coefficients are in agreement with the data. Measured magnetic noise floor of 25 pT/HHz at 1Hz and 100 fT/root Hz at EMR are comparable to best values reported for Metglas-PZT fiber sensors. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4705305]