Effects of annealing temperature on microstructure and ferroelectric properties of Bi0.5(Na0.85K0.15)0.5TiO3 thin films

sBi0.5(Na0.85K0.15)0.5TiO3 (BNKT15) thin films were synthesized by metal-organic decomposition (MOD) at annealing temperatures of 650, 680, 710 and 740 °C, and the effects of annealing temperature on the microstructure, dielectric properties, remnant polarization (2Pr) and leakage current density were studied with X-ray diffractometer, atomic force microscope, precision impedance analyzer, ferroelectric analysis station and semiconductor parameter tester. The results show that the thin film annealed at 710 °C exhibits a typical perovskite structure without predominant orientation and a smooth surface with evenly distributed grains. 2Pr value (67.4 μC/cm2 under 830 kV/cm) and the leakage current density (1.6×10−6 A/cm2 at 170 kV/cm) for BNKT15 thin film annealed at 710 °C are better than those for thin films annealed at other temperatures.