Nonvolatile manipulation of electronic and ferromagnetic properties of NiO–Ni epitaxial film by ferroelectric polarization charge.

NiO–Ni composite films were heteroepitaxially grown on (111)-oriented ferroelectric 0.31Pb(In1/2Nb1/2)O3-0.35Pb(Mg1/3Nb2/3)O3-0.34PbTiO3 (PIN-PMN-PT) single-crystal substrates by pulsed laser deposition. The NiO films prepared in high vacuum are n-type conducting and possess room-temperature ferromagnetism, which originates from oxygen vacancies and the presence of the second Ni phase, respectively. Taking advantage of the electric-field-induced ferroelectric polarization charges, we realized in situ reversible and nonvolatile modulation of both the electrical resistance and magnetism of the film. A relative resistance change of ∼470% is obtained at room temperature, while an appreciable magnetization change of ∼15% was achieved at 50 K by switching the polarization states of PIN-PMN-PT. The coexistence of charge-density-tunable electronic and magnetic properties of NiO–Ni/PIN-PMN-PT heterostructures may provide a strategy to design charge-mediated multiferroic devices for nonvolatile memory and spintronic applications. [ABSTRACT FROM AUTHOR]