Dynamic state switching in nonlinear multiferroic cantilevers

We demonstrate read-write-read-erase cyclical mechanical-memory properties of all-thin-film multiferroic heterostructured Pb(Zr$_{0.52}$Ti$_{0.48})$O$_{3}$ / Fe$_{0.7}$Ga$_{0.3}$ cantilevers when a high enough voltage around the resonant frequency of the device is applied on the Pb(Zr$_{0.52}$Ti$_{0.48})$O$_{3}$ piezo-film. The device state switching process occurs due to the presence of a hysteresis loop in the piezo-film frequency response, which comes from the nonlinear behavior of the cantilever. The reference frequency at which the strain-mediated Fe$_{0.7}$Ga$_{0.3}$ based multiferroic device switches can also be tuned by applying a DC magnetic field bias that contributes to the increase of the cantilever effective stiffness. The switching dynamics is mapped in the phase space of the device measured transfer function characteristic for such high piezo-film voltage excitation, providing additional information on the dynamical stability of the devices.