Characteristics of highly (001) oriented (K,Na)NbO3 films grown on LaNiO3 bottom electrodes by RF magnetron sputtering

(K,Na)NbO3 ferroelectric films were grown on LaNiO3 coated silicon substrates by RF magnetron sputtering. The conductive LaNiO3 films acted as seed layers and induced the highly (001) oriented perovskite (K,Na)NbO3 films. Such films exhibit saturated hysteresis loops and have a remnant polarization (2Pr) of 23 μC/cm2, and coercive field (2Ec) of 139 kV/cm. The films showed a fatigue-free behavior up to 109 switching cycles. A high tunability of 65.7% (@300 kV/cm) was obtained in the films. The leakage current density of the films is about 6.0×10−8 A/cm2 at an electric field of 50 kV/cm.