采用固相反应法制备了(1-x)Li0.05(K0.5Na0.5)0.95NbO3-x(Bi0.5Na0.5)TiO3(LKNN-BNT)无铅压电陶瓷,研究了BNT的添加量x(0,0.005,0.01,0.02)对LKNN-BNT陶瓷的结构与电性能影响。X射线衍射(XRD)分析结果表明当x≤0.005时,陶瓷为正交钙钛矿结构,而当x≥0.01时,陶瓷则转变为四方钙钛矿结构,说明该陶瓷的多型相转变(PPT)区域为0.005
(1-x)Li0.05(K0.5Na0.5)0.95NbO3-x(Bi0.5Na0.5)TiO3(LKNN-BNT) lead-free piezoelectric ceramics was prepared by solid state reaction route.The effect of BNT doping amount x(0,0.005,0.01,and 0.02) on the structure and electrical properties of LKNN-BNT ceramics was investigated.XRD results indicate that the ceramics shows orthorhombic perovskite structure when x≤0.005 while changes to tetragonal one when x≥0.01,suggesting a polymorphic phase transition(PPT) region 0.005〈x〈0.01.SEM analysis investigate that the addition of BNT is in favor of improving the densification.In the PPT region boundary of x=0.005,the ceramics show excellent electrical properties as follows: piezoelectric constant d33=182 pC/N,planar electromechanical coupling coefficient kp=0.351,mechanical quality factor Qm=289,relative dielectric constant εr=1065,and dielectric loss tanδ=0.0329.