Effect of Excess Ratio of Alkali Metal on Microstructure and Ferroelectric Property of K_0.5Na_0.5NbO₃ Thin Film

Abstract

Lead-free K_0.5Na_0.5NbO₃ thin films with different excess ratios of alkali metal were prepared by chemical solution deposition method. The volatilization rate of the K, Na elements at a certain temperature was calculated by EDS analysis. The volatilization rate of K element is 55% and Na element is 10% when the KNN thin film was pre-sintered at the temperature of 375 °C and then final heated at the temperature of 675 °C. The prepared KNN thin films with the right excess ratios (K-55%, Na-10%) obtained uniform and dense microstructure, and gain well ferroelectric property.

Keywords:

• Excess ratio
• alkali metal
• KNN
• microstructure
• ferroelectric property