Sr_(1-x)Ba_xNb_2O_6钨青铜铁电陶瓷的结构与介电性能研究

Structure and Dielectric Properties of Sr_ (1-x)Ba_xNb_2O_6 Ferroelectric Ceramics with Tungsten Bronze Structure

通过固相反应法合成了Sr1xBaxNb2O6(SBN)钨青铜型铁电陶瓷,并对其结构、介电性能进行了系统的研究。结果表明在所研究的成分范围内,SBN陶瓷均形成了四方钨青铜相,但是SBN25陶瓷的主相为焦绿石相,其他3种成分的SBN陶瓷均为四方钨青铜单相。SBN陶瓷均存在一个明显的弥散介电峰,峰值温度随x的增加从室温(SBN25)升高到130℃左右(SBN60);同时峰值温度随频率往高温偏移,为典型的弛豫铁电相变。

Ferroelectric ceramics Sr1-xBaxNb2O6 （SBN） with tungsten bronze structure were synthesized by solid state reaction. Crystal structure and dielectric properties of SBN ceramics were extensively investigated. The results showed that tetragonal tungsten bronze phase was formed in all the SBN ceramics. For SBN25 ceramics, tungsten bronze phase was minor phase, but pyrochlore phase was major phase. Only tetragonal tungsten bronze phase existed in the other ceramics. An obvious diffuse dielectric peak was observed for all the SBN ceramics. And the peak temperature shifted to higher temperature with x and frequency increased. It showed typical relaxor ferroelectric transition.