中文摘要：

在（Na0.5Bi0.5）0.93Ba0.07TiO3中引入过量的Bi3＋,研究富Bi对该组成结构与压电和铁电性能的影响。采用柠檬酸盐法合成了具有单一钙钛矿相的（Na0.5Bi0.5＋x）0.93Ba0.07TiO3（x=0~1.0%）超细粉料。研究结果表明,随着富Bi量的增加,陶瓷样品的晶体结构出现由三方-四方相共存向四方相的转变,Bi的过量对陶瓷样品的显微结构无明显影响。当富Bi量较低（x≤0.6%）时,压电常数和机电耦合系数随富Bi量的增加而缓慢降低。当富Bi量较高（x〉0.6%）时,随着富Bi量的增加,压电常数和机电耦合系数急剧减小。富Bi使陶瓷样品的介电损耗增加,机械品质因数下降。当x≤0.4%时陶瓷样品具有饱和的电滞回线,而当x〉0.4%时电滞回线明显变形。

英文摘要：

The influence of Bi excess on the structure, piezoelectric and ferroelectric properties of （Na0.3 Bi0.5 ）0. 93 Ba0.07 TiO3 composition was examined in this research. Fine and homogeneous （Na0.5 Bi0.5＋x ）0.93 Ba0.07 TiO3 （x= 0~ 1.0 % ） powders with a pure perovskite phase were synthesized by a citrate method. With the increase of excess amount of Bi, a change in the crystal structure from coexistence of rhombohedral and tetragonal phases to tetragonal phase was detected, while no remarkable evolution in microstructure was observed. When x≤0.6%, the piezoelectric constant d33 and electromechanical coupling factor kp tend to slightly decrease with increasing excess amount of Bi. Further increasing the excess amount of Bi above 0.6% led to a rapid degradation of piezoelectric constant d33 and electromechanical coupling factor kp. Moreover, it was found that the Bi excess resulted in an increased dielectric loss tan and a reduced mechanical quality factor Qm. Saturated P-E hysteresis loop were obtained for the specimens with x≤0.4%, and a distortion of measured loops occurred when x〉0.4%.