Nonlinear electric field tuning characteristics of yttrium iron garnet-lead zirconate titanate microwave resonators

This report is on hysteresis and switching associated with electric field (E) tuning of ferromagnetic resonance in a bilayer of yttrium iron garnet (YIG)-lead zirconate titanate (PZT). The tuning is facilitated by piezoelectricity of PZT and mechanical bonding with YIG. For E < 2 kV/cm, the frequency shift delta f is linear with E. For E < 10 kV/cm a pronounced hysteresis is seen in delta f versus E. For E>10 kV/cm, a butterflylike dependence of delta f with an abrupt switch in the sign and magnitude of delta f are measured. The observations are attributed to nonlinearities of the piezoelectric deformation. (C) 2008 American Institute of Physics.