摘要
采用传统烧结工艺制备了Cu掺杂的(Li,Na,K)NbO3基无铅压电陶瓷,研究了Cu掺杂量对陶瓷结构和电学性能的影响。结果表明:当Cu掺杂量x≤1.2%(摩尔分数)时,陶瓷的晶粒度和致密度随Cu掺杂量的增加而增大,在x=1.2%时其相对密度达到最大值94.6%。当x>0.8%时,陶瓷中开始出现杂相,导致其压电性能下降。陶瓷的压电常数d33和机电耦合系数kp在x=0.8%时分别达最大值186 pC/N和33%。Cu的掺杂为受主掺杂,使陶瓷呈现一定的"硬性",陶瓷的机械品质因数Qm由x=0.3%时的162提高到x=1.0%时的318。
（Li, Na, K）NbO3-based lead-free piezoceramics doped with Cu were synthesized by a conventional mixed-oxide method. The crystalline phase, microstructure, and electrical properties of the ceramics were investigated with a special emphasis on the influence of Cu doping amounts. The results show that the grain size and the density increased with increasing Cu doping amounts when the molar fraction of Cu x≤1.2%, and the maximum density of 94.6% was obtained for the ceramic with x=1.2%. The impurity of K4CuNb8O23 was detected when x0.8%, which leads to the decrease in piezoelectric properties. So the piezoelectric constant d33 and the electromechanical coupling factor kp of the ceramic with x=0.8% reach their maximum values of 186 pC/N and 33%, respectively. The B-site substitutions of Cu ions acts as acceptors and changes the property of L6NKN-Cux to be ＂hard＂, leading to the increment of the mechanical quality factor Qm from 162 for the sample with x=0.3% to 318 for the sample with x=1.0%.
基金
高等学校博士学科点专项科研基金资助项目(20090006110010)
关键词
压电陶瓷
掺杂
烧结
电学性能
致密度
piezoceramics
doping
sintering
electric properties
density
