Magnetoelectric interactions in bilayers of yttrium iron garnet and lead magnesium niobate-lead titanate: Evidence for strong coupling in single crystals and epitaxial films

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 parallel to < 1i1 > and is minimum for H parallel to < 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. (c) 2005 American Institute of Physics.