钡掺杂对Bi1.5ZnNb1.5O7陶瓷结构和介电性能的影响

Effect of Barium Doping on Structure and Dielectric Properties of Bi1.5ZnNb1.5O7 Ceramics

采用固相烧结法制备了Bi1.5-xBaxZnNb1.5O7(x=0.05,0.10,0.15,0.20,物质的量比)陶瓷,研究了钡掺杂量x对陶瓷烧结性能、结构和介电性能的影响。结果表明:掺杂钡后陶瓷的烧结温度从1 050℃降至960℃,其物相均为单一焦绿石相,且其衍射峰随钡掺杂量的增加向小角度方向偏移;陶瓷的介电常数和介电损耗随钡掺杂量的增加而增大;不同频率下,不同钡掺杂量陶瓷在低温区域均出现介电弛豫现象;介电弛豫峰随钡掺杂量的增加逐渐宽化和平坦化,且向高温方向移动;随着钡掺杂量的增加,陶瓷的弛豫程度先减小后增大,弛豫激活能和温度系数先增大后减小。

Bi1.5-xBaxZnNb1.5O7(x=0.05,0.10,0.15,0.20,molar ratio)ceramics were prepared by solid sintering method.The effects of barium doping on sintering property,structure and dielectric property of the ceramics were studied.The results show that the sintering temperature of the ceramics decreased from 1 050℃to 960℃after barium doping.The phase of the ceramics was composed of single pyrochlorite,and its diffraction peak shifted to a small angular direction as the doping amount of barium increased.The dielectric constant and dielectric loss of the ceramics increased with increasing barium doping amount.Under different frequencies,the ceramics with different barium doping amount showed dielectric relaxation at low temperatures.The dielectric relaxation peak became widening and flattening with increasing barium doping amount,and shifted to high temperature directions.With increasing barium doping amount,the dielectric relaxation degree of the ceramics decreased first and then increased,and the relaxation activation energy and temperature coefficient increased first and then decreased.