Synthesis and characterization of multiferroic Pb(Zr,Ti)O₃/CoFe₂O₄/Pb(Zr,Ti)O₃ layered composite thin films by chemical solution deposition

Abstract

Multiferroic Pb(Zr,Ti)O₃/CoFe₂O₄/Pb(Zr,Ti)O₃ layered thin films were synthesized on Pt/TiO_x/SiO₂/Si substrates by chemical solution deposition using metal–organic precursor solutions. Layered composite films composed of polycrystalline perovskite Pb(Zr_0.52Ti_0.48)O₃ and spinel CoFe₂O₄ phases with no secondary phases were successfully synthesized by controlling conditions such as the coating process. The layered structure of the Pb(Zr_0.52Ti_0.48)O₃/CoFe₂O₄/Pb(Zr_0.52Ti_0.48)O₃ was confirmed by scanning electron microscope observations. These layered films exhibited sufficiently high insulating properties, as well as ferroelectric polarization (P)-electric field (E) and ferromagnetic magnetization (M)-magnetic field (H) hysteresis loops at room temperature. Typical ferroelectric oxide strain behavior was observed under a driving AC (alternate current) field. Furthermore, due to magnetoelectric interaction between the ferroelectric and ferromagnetic (magnetostrictive) layers, the ferroelectric properties of the films altered under an applied magnetic field (approximately 0.5 T).