All-thin-film multiferroic heterostructured cantilevers in linear and nonlinear dynamic regimes

We report on fabrication and characterization of all-thin-film multiferroic magnetoelectric (ME) cantilever devices and their different modes of operation in both linear and nonlinear dynamic regimes. The devices are built on micro-electromechanical system (MEMS) platforms that involve stress-engineered designs based on \textit{silicon oxide/nitride/oxide (ONO)} stacks. The ME layers consist of a magnetostrictive Fe$_{0.7}$Ga$_{0.3}$ thin film and a Pb(Zr$_{0.52}$Ti$_{0.48}$)O$_{3}$ piezoelectric thin film. The resonant frequency was found to display DC magnetic field dependence indicative of the interplay between the anisotropy and Zeeman energies. In the magnetically-driven mode, the harvested peak power at 1 \textit{Oe} is 0.7\textit{ mW/cm}$^{3}$ (RMS) at the resonant frequency (\textit{3.8 kHz}) and the quality factor also displays strong dependence on the DC magnetic bias. In certain conditions, the multiferroic devices show nonlinear behaviors important to logic implementation and parametric amplification.