Observation of magnetoelectric effect in epitaxial ferroelectric film/manganite crystal heterostructures

A multiferroic heterostructure is constructed by growing an epitaxial piezoelectric $\mathrm{Pb}({\mathrm{Zr}}_{0.3},{\mathrm{Ti}}_{0.7}){\mathrm{O}}_3$ film on a magnetostrictive layered manganite single crystal of composition ${\mathrm{La}}_{1.2}{\mathrm{Sr}}_{1.8}{\mathrm{Mn}}_2{\mathrm{O}}_7$. The efficient mechanical coupling at the interface results in a remarkable magnetoelectric (ME) effect. The ME voltage is $\sim 87\%$ of the theoretical value predicted by a phenomenological thermodynamic model. The ME effect peaks at the ferromagnetic transition temperature of the manganite, a consequence of its magnetostrictive characteristics.