(Invited) Fabrication and Dielectric Properties of BaTiO3 Thin Films on Polycrystalline Ni Foils

The BaTiO₃ (BTO) thin films were deposited on polycrystalline Ni foils using a chemical solution approach. We show that the interface between the BTO film and the Ni foil plays a critical role in determining the dielectric and magnetoelectric (ME) properties of this flexible assembly. A pretreatment process of nickel foils with hydrogen peroxide (H₂O₂) solution has been conducted to form thin nickel oxide layers on the surfaces for the growth of BTO films. Both the concentration of H₂O₂ solution and the pretreated time were found to strongly affect the dielectric constant of BTO films,  which is likely to be related to the evolution of nickel oxide at the interface during the growth of BTO films. The growth dynamics was systematically studied to optimize the single phase BTO films with good dielectric properties. Our results have demonstrated that not only a well-controlled interface between the BTO film and the Ni substrate can be achieved, but also an good dielectric and ME performance can be accomplished.