K,Na比对KNNT陶瓷性能的影响

采用传统固相反应法制备了（KxNa1-x）（Nb0.7Ta0.3）O3 （KNNT）系列无铅压电陶瓷. 通过XRD和SEM分析方法研究了样品的结构, 晶格常数变化和微观形貌. 研究发现晶格常数在x = 0.40附近发生了不连续性变化, 微观结构随K含量的增多表现出微小的差异, 压电常数d33,平面机电耦合系数kp在x = 0.40-0.55较宽范围内发生了较小的变化. K含量为0.40时获得了压电性能最优的KNNT陶瓷, d33达到204 pC/N, 机电耦合系数kp为46%, kt为44%.

Influence of compositonal ratio K/Na on properites in KNNT ceramcis

Lead-free （KxNa1-x）（Nb0.7Ta0.3）O3 （KNNT） with x=0.30-0.80 were prepared by a conventional solidstate reaction method. The crystalline structure, the variation of lattice parameters and microstructure were investigated by XRD and SEM methods. The existence of a change in the line slopes of lattice parameter variation with x is verified in the vicinity of x=0.40. The microstructure of KNNT ceramics exhibits little difference with the increasing of K contents. The piezoelectric constant d33, and planar electromechanical coupling coefficient kp show slight change with x=0.40-0.55. The ceramics with K content is 0.4 have the high piezoelectric values of d33 -204 pC/N, kp-46% and kt-44%.