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

Polycrystalline Bi0.5 Na0.5 TiO3 (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.