Growth Behavior and Electrical Properties of a (Na0.5K0.5)NbO3Thin Film Deposited on a Pt/Ti/SiO2/Si Substrate Using RFMagnetron Sputtering

A crystalline (Na0.5K0.5)NbO3 (NKN) phase was formed for a film grown at 600°C, but a K5.75Nb10.85O30 (KN) second phase was also observed in this film. Formation of the KN phase was due to the evaporation of Na2O. A homogeneous NKN phase was developed in the film grown at 300°C and annealed at 800°C under a Na2O atmosphere. This film exhibited the following good electric and dielectric properties: a high dielectric constant of 237.4 with a dissipation factor of 0.93% at 100 kHz, a low leakage current density of 1.0 × 10−8 A/cm2 at 0.1 MV/cm2, and the high Pr and d33 values of 21.1 μC/cm2 and 64.5 pm/V, respectively.