Properties of Nb-doped lead scandium niobate titanate thin films prepared by a sol–gel method

Lead scandium niobate titanate (Pb[Sc 1/2 Nb 1/2 ) 0.57 Ti 0.43 ]O 3 ) thin films with 0.5 mol% Nb doping were prepared by a sol–gel method. Films annealed at temperatures greater than 600°C crystallized into a single phase perovskite structure. The films were transparent and crack-free with uniform thickness and an average grain size of 1.1 μm. The dielectric constant and dissipation factor measured at 1 kHz for a film annealed at 700°C were 1370 and 0.022, respectively. Ferroelectricity was confirmed by the presence of hysteresis loops, with a remanent polarization of 20 μC/cm 2 and coercive field of 35 kV/cm. The piezoelectric coefficient ( d 33 ) of a poled film was 98 pm/V. Dielectric, ferroelectric, and piezoelectric properties of the films were enhanced through annealing and poling after deposition of the top gold electrode.