中文摘要：

为降低成本，采用传统电子陶瓷工艺制备了（Na0．5K0．5-xLix）NbO3（x=0．057-0．066）无铅压电陶瓷。Li取代K可以明显提高样品的居里温度（tc），x=0．066时样品的tc高达510℃，比纯（Na0．5K0.5）NbO3陶瓷高70℃左右。x=0．064时样品的d33高达212pC／N，kp为45．7％。x=0．063—0．066时样品的tanδ均低于0．020。特别是，x=0．066的样品经450℃退火24h，d33仍高达125pC／N。实验表明（Na0．500K0．434Li0．066）NbO3是高性能的高温无铅压电陶瓷。

英文摘要：

In order to reduce the cost, （Na0.5K0.5-xLix）NbO3 （x = 0.057 - 0.066） lead-free piezoelectric ceramics were fabricated by the traditional electroceramic processing. It is found that Curie temperature （tc） of the ceramic samples substituted by Li for K is obviously raised, tc of the sample of x = 0.066 is as high as 510 ℃ with 70 ℃ higher than the pure （Na0.5K0.5）NbO3 ceramic. The piezoelectric constant （d33） is as high as 212 pC/N, and planar electromechanical coupling factor （kp） reaches 45.7% for the sample ofx = 0.064. The dielectric loss （tanδ） of the samples ofx = 0.063 - 0.066 is below 0.020. Especially, the sample of x = 0.066 still has a high d33 value of 125 pC/N after 24 h annealing at 450 ℃. These results indicate that （Na0.500K0.434Li0.066）NbO3 is a high-temperature lead-free piezoelectric ceramics with high performance.