Electric-field control of magnetism in the flexible CoFeB/P(VDF-TrFE) multiferroic heterostructures

Flexible multiferroic heterostructures of ferromagnetic Co40Fe40B20/ferroelectric copolymer poly-vinylidene fluoride-trifluoroethylene [CoFeB/P(VDF-TrFE)] were fabricated by DC sputtering. The structure, ferroelectric behaviours along with remnant polarization (2Pr) of 2.4 μC/cm2 at room temperature, saturated magnetizations around 900 emu/cm3 were measured in the novel composites. Moreover, the direct electric field control of magnetic properties and the mechanisms of magnetoelectric (ME) coupling in the flexible CoFeB/P(VDF-TrFE) heterostructures were investigated, and the strong strain-mediated ME effect originating from voltage-induced piezo-strain was demonstrated. These results show the good prospects in application of flexible spintronic devices.