Preparation and Properties of Lithium-doped K0.5Na0.5NbO3 Thin Films by Chemical Solution Deposition

Lithium doped K_0.5Na_0.5NbO₃ films were fabricated by chemical solution deposition on Pt/TiO₂/SiO₂/Si substrates. Homogeneous and stable precursor solutions were prepared by controlling the reaction of starting metal alkoxides. Perovskite KNN single phase thin films were successfully synthesized on Pt/TiO_x/SiO₂/Si substrates. The 1.2 mum-thick KLNN film annealed at 650degC exhibited a ferroelectric polarization hysteresis loops at -250degC. The loop at room temperature is round in shape indicating the film contains leakage components. Dielectric constant under zero bias is 490 at room temperature. Typical upside-down butterfly DC bias-capacitance curve was obtained in the KLNN film capacitors at room temperature, indicating polarization reversal occurs in the obtained KLNN films.