Improved electrical properties of Nd-doped K0.5Bi4.5Ti4O15 thin films prepared by chemical solution deposition

K0.5Bi4.5Ti4O15 (KBTi) and K0.5Bi4Nd0.5Ti4O15 (KBNdT) thin films were prepared using a chemical solution deposition. For all samples, layered perovskite structures with a single phase and a good crystalline structure were observed in the X-ray diffraction patterns and the Raman scattering spectra. The microstructures were composed of fine grains without cracks in the scanning electron microscope results. The KBNdT thin film exhibited a better hysteresis loop than the KBTi thin film. For the KBNdT thin film, the remnant polarization (2Pr) was 45 μC/cm2 and the leakage current density was approximately half an order of magnitude lower than that of the KBTi thin film. In addition, no polarization fatigue was observed in the KBNdT thin film up to 4.44×109 switching cycles. Therefore, Nd-doping is an effective method to improve the ferroelectric properties of the KBTi thin film.