Characterization of Pb(Zr _0.52Ti _0.48)O ₃/BiFeO ₃ multilayer thin films prepared by a sol-gel method

Multiferroic Pb(Zr _0.52Ti _0.48)O ₃/BiFeO ₃ multilayer thin films were fabricated by the spin-coating method on Pt/Ti/SiO ₂/p-Si(100) substrates alternately using Pb(Zr _0.52Ti _0.48)O ₃ and BiFeO3 metal alkoxide solutions. The PZT/BFO multilayer thin films show the formation of layers and a change of lattice constant caused by different structure of each other. The coating and heating procedure was repeated several times to form Pb(Zr _0.52Ti _0.48)O ₃/BiFeO ₃ multilayer films. All films showed the typical XRD patterns of the perovskite polycrystalline structure without the presence of a second phase such as Bi ₂Fe ₄O ₃. Pb(Zr _0.52Ti _0.48)O ₃/ BiFeO ₃ multilayer films showed a uniform and small grain size rather than pure Pb(Zr _0.52Ti _0.48)O ₃ and BiFeO ₃ films. We think that the crystal growth of the upper BiFeO ₃ layers can be influenced by the lower Pb(Zr _0.52Ti _0.48)O ₃ layers, and choosing the initial Pb(Zr _0.52Ti _0.48)O ₃ layer or a seeding layer has controlled the microstructural behavior of the resultant film. Leakage current density of the Pb(Zr _0.52Ti _0.48)O ₃/BiFeO ₃ multilayer film was 5.74 × 10 ^-6 A/cm ² at 150 kV/cm.