Lead-free KNbO3 piezoceramics synthesized by pressure-less sintering
Lead-free KNbO3 piezoceramics synthesized by pressure-less sintering
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DOI：
10.1016/j.jeurceramsoc.2005.03.209
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发表时间：
2005
影响因子：
5.7
通讯作者：
K. Kakimoto;Izumi Masuda;H. Ohsato
中科院分区：
文献类型：
--
作者：
K. Kakimoto;Izumi Masuda;H. Ohsato
在优化的热处理条件下，采用无压烧结法，添加少量La 2 O3和Fe 2 O3，成功地合成了致密的KNbO 3陶瓷。X射线衍射（XRD）分析表明，KNbO 3形成（K1-xLax）（Nb 1-xFex）O3固溶体，并且根据添加剂含量的不同，晶体系统发生变化，在x为0.020时从正交晶系变为四方晶系，在x为0.200或更高时从四方晶系变为立方晶系。x=0.002的样品表现出正交对称性，并表现出最佳的饱和铁电滞回线，其最大回复极化（Pr）为18μC/cm 2，与文献报道的热压法制备的纯KNbO 3陶瓷的值相当。该样品还显示出0.17的平面机电耦合比（kp）和0.48的厚度模式（kt）。压电d33常数为98 pC/N。
Dense KNbO3ceramics have been successfully synthesized by pressure-less sintering under optimized heat-treatment conditions using a small amount of La2O3and Fe2O3additives. X-ray diffraction (XRD) analysis revealed that KNbO3forms (K1−xLax)(Nb1−xFex)O3solid solutions and changes in the crystal system, depending on the additive content, from orthorhombic to tetragonal at x of 0.020, and from tetragonal to cubic at x of 0.200 or higher. The x=0.002 specimen showed orthorhombic symmetry and demonstrated the best saturated ferroelectric hysteresis loop with largest remanent polarization (Pr) of 18μC/cm2, which is comparable to the value reported for pure KNbO3ceramics fabricated by hot pressing. This specimen also showed a planar electromechanical coupling ratio (kp) of 0.17 and thickness mode (kt) of 0.48. The piezoelectric d33constant was 98pC/N.