抄録
Copper-doped potassium sodium niobate CuO-(K0.48Na0.52)NbO3 (CuO-KNN) ceramics was fabricated via a hydrothermal method. An extra post- annealing process in air was adopted to analyze the relationship between mechanical quality factor and aging phenomenon. Quality factor (Qm) of CuO-KNN ceramics decreases to a small value after post-annealing and recovers gradually over several hours. This phenomenon is attributed to the rearrangement of oxygen vacancies in the domains. On the basis of such relationship, a new method of post-annealing in argon was proposed to enhance the Qm. Post-annealing in argon can significantly increase the Qm of CuO-KNN from 880 to approximately 1500 through increasing the amount of oxygen vacancies, which would impede movement of the domain structures. On the contrary, Qm decreases after post-annealing in oxygen atmosphere. High vibration velocity (0.9 m/s) was obtained, indicating that CuO-KNN is a promising material for high power applications.
