Energy harvesting properties of all-thin-film multiferroic cantilevers

We have measured electromagnetic energy harvesting properties of all-thin-film magnetoelectric (ME) heterostructures on Si cantilevers. The devices are built on a silicon oxide/nitride/oxide stack, and 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 harvested peak power at 1Oe is 0.7 mW/cm(3) (RMS) at the resonant frequency (3.8 kHz) with a load of 12.5 k Omega. The resonant frequency was found to display DC bias magnetic field dependence indicative of a magnetization canting with respect to the cantilever easy axis as a result of interplay between the anisotropy and Zeeman energies. (C) 2011 American Institute of Physics. [doi:10.1063/1.3662037]