Multiferroic thin film via SrRuO3–BaTiO3 vertically aligned nanocomposite design

The design of a nanocomposite system with a ferroelectric phase and a ferromagnetic phase is essential to achieve multiferroics due to the limited one-phase multiferroic material in nature. Ferromagnetic SrRuO3 (SRO) and ferroelectric BaTiO3 (BTO) have been selected to achieve the SRO-BTO nanocomposite thin film. The film exhibits excellent crystal quality owing to the perfect lattice matching of both phases with the SrTiO3 substrate, and very thin SRO nanopillars (∼5 nm) have been obtained. Because of the anisotropic nature of the SRO nanopillars, magnetic anisotropy has been obtained for the nanocomposite thin film, and the Curie temperature (Tc) can be determined to be 152 K. Furthermore, switchable piezoelectric behavior of the nanocomposite film with a maximum d33 value of ∼70 pm/V is obtained by the piezoelectric force microscopy measurement. Overall, the SRO-BTO nanocomposite system presents the desirable multiferroic response, which is promising for future magnetoelectric device integration.