Ferroelectric (K_0.44Na_0.52 Li_0.04)(Nb _0.86Ta_0.10Sb_0.04)O₃ thin films prepared by pulsed laser deposition

Lead-free ferroelectric (K_0.44 Na_0.52Li _0.04)(Nb_0.86Ta _0.10Sb_0.04)O ₃ (KNN-LT-LS) thin films have been prepared by a pulsed laser deposition process on Pt/Ti/SiO₂/Si substrates. Morphologies, structures and electrical properties of KNN-LT-LS thin films have been investigated as a function of deposition temperature from 680°C to 740°C. X-ray diffraction analysis indicates that KNN-LT-LS thin films are a perovskite phase with a preferential (001) orientation. The dielectric constant and loss tangent of KNN-LT-LS films deposited at 740°C are 1450 and 7.2% at 1 kHz, respectively. The P-E hysteresis loops show that the KNN-LT-LS thin films possess improved ferroelectric properties. The remnant polarization and the coercive field of the films are 7.69 μC/cm² and 40.8 kV/cm, respectively.