B_(2)O_(3)掺杂对0.76BF-0.24BT高温无铅压电陶瓷结构与性能影响

Effect of B_(2)O_(3)doping on structure and properties of 0.76BF-0.24BT high temperature lead-free piezoelectric ceramics

为研究掺杂B_(2)O_(3)对陶瓷的影响,采用固相合成法制备了0.76BiFeO_(3)-0.24BaTiO_(3)-xB_(2)O_(3)(简称0.76BF-0.24BT-x BO)高温无铅压电陶瓷,x为摩尔分数。对0.76BF-0.24BT-x BO陶瓷相结构、微观形貌组织、电学性能、居里温度以及退极化温度进行测试分析。XRD分析表明所有样品均为纯三方钙钛矿结构。观察陶瓷微观形貌,发现晶粒分布均匀,晶界之间有液相存在,且晶粒尺寸随着x增加而增大。陶瓷最佳烧结温度从960℃降至940℃。当x=0.1时,压电常数和剩余极化强度达到最大值,分别为101 pC·N^(-1)、21.5μC·cm^(-2)。0.76BF-0.24BT-x BO陶瓷有着良好的高温稳定性:居里温度T_(C)为585℃,退极化温度T_(d)=560℃。研究结果表明,掺杂B_(2)O_(3)具有改善0.76BF-0.24BT陶瓷微观形貌组织、降低烧结温度和提高电学性能的作用。

In order to study the effect of doping B_(2)O_(3)on ceramics,0.76BiFeO_(3)-0.24BaTiO_(3)-xB_(2)O_(3)(0.76BF-0.24BT-xBO)high temperature lead-free piezoelectric ceramics were prepared by solid phase synthesis method,x is the mole fraction.The effects of different BO content on phase structure,microstructure,electrical properties,Curie temperature and depolarization temperature of ceramics were studied.XRD analysis show that all samples are of rhomb tripartite perovskite structure.The observation of microstructure shows that the grain distribution is uniform,and there is liquid phase between grain boundaries,and the grain size increases with the increase of x.The optimal sintering temperature of ceramics was reduced from 960℃to 940℃.When x=0.1,the excellent electrical properties are obtained:d_(33)=101 pC·N^(-1),Pr=21.5μC·cm^(-2).0.76BF-0.24BT-xBO ceramics have good high temperature stability:T_(C)=585℃,T_(d)=560℃.The results show that the doping of B_(2)O_(3)can improve the microstructure,reduce the sintering temperature and improve the electrical properties of 0.76BF-0.24BT ceramics.