LaAlO_3掺杂的(K_(0.44)Na_(0.52)Li_(0.04))NbO_3无铅压电陶瓷电学性能研究(英文)

Effect of LaAlO_3 on Dielectric Properties of ( K_(0.44)Na_(0.52)Li_(0.04) ) NbO_3 Ceramics

采用传统的固相反应法制备了(1-x)(K0.44Na0.52Li0.04)NbO3-xLaAlO3(KNLN-xLA)无铅压电陶瓷,研究了LaAlO3的掺杂对陶瓷结构和电学性能的影响.X光衍射结果表明,所有的样品都显示出纯的钙钛矿结构,没有杂相生成.添加适量的LA使陶瓷的正交-四方相变温度降低至室温附近.当LaAlO3的掺杂量为0.50mol%的时候,样品的性能达到最佳:介电损耗tanδ=2.9%,居里温度TC=441℃,同时样品的密度达到最大.以上数据表明,该陶瓷材料是一种极具应用潜力的无铅压电陶瓷材料.

Lead-free piezoelectric ceramics of （1 -- x） （K0.44 Na0.52 Li0.04 ） NbO3-xLaA103 （KNLN- xLA） system have been investigated in this work. The phase structure and electrical properties of the ceramics were symmetrically investigated. The X-ray techniques indicate that LA diffu- ses into the KNLN lattice to form a new homogenous solid solution. The proper addition of LA shifts the polymorphic phase transition to near room temperature, and a coexistence of ortho- rhombic and tetragonal phases is formed. It is found that the KNLN-0. 005LA ceramics exhibit optimum overall properties （dielectric loss tanS= 2.9% and Curie temperature Tc = 441C）, meanwhile, the densification is promoted as x=0. 005, suggesting that this material could be a promising lead-free piezoelectric candidate for piezoelectric applications.