锰掺杂对(K_(0.5)Na_(0.5))NbO_3-LiNbO_3压电陶瓷结构和性能的影响

Effects of Doping MnO_2 on Microstructure and Piezoelectric Properties of (K_(0.5)Na_(0.5))NbO_3-LiNbO_3 Ceramics

采用传统陶瓷制备工艺制备了(K0.5Na0.5)NbO3-LiNbO3-xMnO2压电陶瓷,分析了陶瓷样品的微观组织结构。实验结果表明,随MnO2掺杂量的增多,陶瓷由四方相转变为正交相,晶粒的均匀性下降并生成K3LiNb6O17相。研究了MnO2不同掺杂量对陶瓷压电性能的影响。结果表明,随锰掺杂量的增加,材料逐渐变"硬",机电耦合系数kp和压电常数d33逐渐减小,同时Qm逐渐增大;当MnO2含量为0.8%(质量分数)时,陶瓷的机械品质因数达到最大,此时陶瓷的压电性能为:kp=0.34,kt=0.43,d33=110pC/N,Qm=401.3。

Piezoelectric ceramics （K0. 5 Na0. 5 ） NbO3-LiNbO3-xMnO2 are prepared by traditional ceramic process. The phase structure is analyzed. The results show that the phase structure changes from tetragonal phase to orthogonal phase with the content of MnO2 increasing. The new phase K3 LiNb6 O17 is formed. The effect of MnO2 doping on the piezoelectric properties is investigated. When the content of MnO2 increases, the mechanical coupling factor kp and piezoelectric constant d33 decrease, while the mechanical quality factor Qm increases. When the content of MnO2 is 0. 8%, the piezoelectric properties of the ceramic are as follows： kp=0. 34, kt=0. 43, d33=110pC/N, Qm=401.3, respectively.