摘要：以Na2C2O4, K2C2O4·H2O和Nb2O5为原料用化学合成法制备了Na0.53K0.47NbO3（简称KNN）粉体，用原位合成工艺制备LiBiO3对KNN进行掺杂。通过热压烧结工艺制备了(1-x)KNN-xLBO（摩尔分数x为0.05、0.075、0.08）陶瓷。工艺条件为：烧结温度1080℃，压力10.2MPa，保温6h。使用X射线衍射、扫描电子显微镜（SEM）对KNN-LBO透明陶瓷片样品的结构、形貌进行了分析。用频谱仪和d33测量仪测量了样品的压电性能。结果表明：随LiBiO3含量增加，陶瓷样品的介电常数r、压电应变常数d33、机电耦合系数kp、kt、介电损耗、体积电阻率会有所降低。LBO摩尔百分数为7.5% 的KNN陶瓷的d33、kp、kt、体积电阻率分别为：80.5pC/N、0.169、0.0155、2.308×108，r与tanδ值相对较小。
关键词：铌酸钾钠陶瓷；无铅压电材料；热压烧结；压电性能
Abstract:Using Na2C2O4, K2C2O4•H2O and Nb2O5 as raw materials, the Na0.53K0.47NbO3 (KNN) powder were prepared by chemical synthesis. The LiBiO3 was synthesized in situ as additives of KNN ceramics. The (1-x)KNN-xLBO (x = 0.05、0.075、0.08) were hot-press sintered under a pressure of 10.2 MPa at 1080 ℃ for 6 hours. The crystalline structure and micro-morphology of the ceramics were analyzed by an X-ray diffractometer, scanning electron microscopy (SEM). The piezoelectric parameters were measured by using an impedance analyzer and a d33 meter. The results showed that the piezoelectric constant d33, electromechanical coefficient kp、kt, dielectric permittivity r, dielectric loss tanδ and density of the ceramics were decreased as the LBO content increased. The d33, kp, kt and density of the KNN with 7.5% LBO were found to be 80.5 pC/N、0.169、0.0155、2.308×108 respectively, r and tanδ value is relatively small.
Keywords: potassium sodium niobate ceramics; lead-free piezoelectric materials; hot-press sintering process; piezoelectric properties
