Ferroelectric and non-linear dielectric characteristics of Bi0.5Na0.5TiO3 thin films deposited via a metallorganic decomposition process

Abstract

Polycrystalline Bi0.5Na0.5TiO3 (NBT) thin films have been successfully fabricated via a metal organic decomposition process on Pt/Ti/SiO2/Si substrates. The structural evolution of the as-prepared thin films annealed over the moderate temperature range 500–700 °C is studied. NBT thin films annealed at 700 °C are of single phase NBT perovskite type. They exhibit a well-defined P-E hysteresis loop at room temperature. The measured dielectric constant is 465–410 over the frequency range of 1 kHz to 1 MHz. The corresponding dielectric loss is ∼10−2. The measured capacitance-voltage curve shows strong non-linear dielectric behavior leading to a high tunability of the dielectric constant, up to 14% at 1 MHz.