Ferroelectric and optical properties of Pb(Zr_xTi_1-x)O₃ bilayers

The uniform, dense, and crack-free PbZr_0.4Ti_0.6O₃/ PbZr_0.5Ti_0.5O₃ bilayer with (100)-preferred crystal orientation and a single perovskite phase was fabricated on LaNiO₃-coated Si substrate by using chemical solution deposition. The bilayer exhibits excellent ferroelectric properties, remnant polarization of 64 μC/cm² and coercive field of 43.6 kV/cm. The prism-film coupling measurement indicates that four transverse electric modes can be excited in the system of Si/LaNiO₃/PbZr_0.5 Ti_0.5O₃/PbZr_0.4Ti_0.6 O₃ and the light can be effectively confined to propagate in the guiding-layer. The refractive index and thickness for each film were obtained by solving the mode eigen-equation of the waveguide.