No abstract

The strength of magnetoelectric (ME) coupling at 10Hz–3MHz has been measured in trilayers of Fe, Co, or Ni and lead zirconate titanate (PZT). The strongest ME coupling is measured for trilayers with Ni and the weakest in Co. Data on ME voltage coefficient αE versus bias magnetic field H for Fe–PZT–Fe show unique features including zero crossing and sign reversal. Measurements of frequency dependence of αE reveal a giant ME coupling due to the electromechanical resonance at 200–300kHz for radial modes and at ∼2.7MHz for thickness modes. Theoretical estimates of field and frequency dependence of αE are in very good agreement with the data.

The nature of low-frequency magnetoelectric (ME) coupling has been investigated in bilayers of single crystal lead magnesium niobate-lead titanate (PMN-PT) and yttrium iron garnet (YIG). Samples with (001) PMN-PT and polycrystalline, single crystal, or epitaxial thin films of YIG were studied. The ME coupling is the weakest in bilayers with polycrystalline YIG. A dramatic strengthening of ME interactions occurs in samples with single crystal (111) YIG. The strongest ME coupling occurs in bilayers with (110) epitaxial YIG film. The voltage coefficients show significant variation with the orientation of the bias magnetic field H; it is maximum for H‖⟨1i¯1⟩ and is minimum for H‖⟨001⟩. The transverse coefficient increases linearly with increasing thickness of YIG film. Data analysis reveals that strong magnetomechanical coupling in thin film YIG is the cause of enhancement in the ME coupling.