Resonance magnetoelectric effects in a layered composite under magnetic and electrical excitations

A novel three-layer composite consisting of a lead zirconate titanate (PZT) substrate, a PZT film on one side, and a film of ferromagnetic alloy on the other side is fabricated and used for studies on the nature of magneto-electric (ME) interactions. The strain mediated ME voltage under an ac magnetic excitation is compared with the voltage produced by pure piezoelectric response of the sample to an ac electric field. The ME voltage response measured across PZT substrate or PZT film under an ac magnetic field shows peaks at bending modes and longitudinal acoustic modes, with a higher voltage at bending mode than for the longitudinal acoustic mode. A variation in the bending mode frequency with bias magnetic field or electric field is observed and is attributed to variation in the Young’s modulus of the magnetic or piezoelectric layers. Estimates of resonance frequencies and ME coefficients are in agreement with the data. Under an ac electric excitation, piezoelectric effects result in a resonance in the voltage measured across the PZT substrate and film. A quantitative agreement is inferred between the measured ME voltage and the voltage produced under an ac electric field.