Mg^(2+)掺杂对BBTI-BIT陶瓷的结构与电学性能影响的研究

Structural and Electrical Properties of Mg^(2+)-doped BBTI-BIT Ceramics

采用固相法制备BaBi_(8)Ti_(7-x)Mg_(x)O_(27-δ)(x=0,0.2,0.4,0.6,0.8)共生铋层状无铅压电陶瓷样品,研究Mg^(2+)含量对陶瓷样品的结构、电学性能及其温度稳定性的影响。结果表明:所有陶瓷样品均呈单一的相结构;随着Mg^(2+)含量的增加,介电常数与介电损耗均呈现减小的趋势,样品在高温下阻抗和激活能均增大。此外,一定含量的Mg^(2+)会使晶粒由片状转为颗粒状等轴晶粒,这有利于陶瓷样品压电性能的提升。当x=0.6时,综合电性能达到最佳,居里温度约为480℃;压电常数为18.8 p C·N^(-1),约为未掺杂样品的250%。

BaBi_(8)Ti_(7-x)Mg_(x)O_(27-δ)(x=0,0.2,0.4,0.6,0.8)intergrowth bismuth layered lead-free piezoelectric ceramics were prepared by using the conventional solid-state reaction method.The effect of Mg^(2+) on structure,electrical properties and temperature stability of the ceramics was studied.All the samples have a single phase structu re.With increasing content of Mg^(2+),both the dielectric constant and dielectric loss showed a decreasing trend,while the impedance and activation energy increase at high temperatures.In addition,a small quantity of Mg^(2+) resulted in a variation in the microstructure from plate-like grains to particle-like grains,leading to an improvement in piezoelectric properties of the ceramics.The sample with x=0.60 exhibited optimum electrical properties,with Curie temperature of about 480℃and piezoelectric constant(d_(33))of 18.8 pC·N^(-1),which is higher than that of the undoped sample by about 250%.