Enhancement of Magnetoelectric Coupling in Ferroelectric Vinylidene Fluoride/Ferroelectric Cobalt by insertion of a dielectric layer of Magnesium Oxide.

Poly (vinylidene fluoride), or PVDF combines the advantages of organic based electronics with the useful bi-stable polarization characteristic of ferroelectricity. Magnetoelectric coupling between PVDF, and ferromagnetic cobalt thin films has been well established. Because VDF thin films may be deposited in vacuum, the interface between Co and VDF is clean and sharp, with little to no oxidation. We studied magnetoelectric coupling in these heterostructures, with VDF deposited directly on Co without breaking vacuum. This pristine interface resulted in very weak magnetoelectric coupling. The introduction of oxides of cobalt between these layers from exposure in air resulted in an increase in the surface coupling but presented challenges of surface purity and irreproducibility. Thus, we investigated the effect of controlled growth of a dielectric with high K, MgO. We focus on the growth and heat treatment of MgO on ferromagnetic cobalt. Consequently, we examine the interfacial interaction between the Cobalt, MgO and VDF layers and analyze how this affects the out of plane magnetic anisotropy of Cobalt.