钨青铜Sr_xBa_(1-x)Nb_2O_6陶瓷的制备及介电性能研究

Preparation and dielectric properties study of tungsten bronze Sr_xBa_(1-x)Nb_2O_6 ceramics

以SrCO3、BaCO3和Nb2O5为原料,采用传统固相法制备了SrxBa1-xNb2O6(SBN,x=0.49～0.56)无铅压电陶瓷。研究了SBN陶瓷组分及烧结温度对其相结构、微观形貌和介电性能的影响。结果表明,所有陶瓷组分在1380℃下烧结均可获得钨青铜结构单相。随着x值的增大,陶瓷致密化速度减慢,晶粒生长趋向均匀,介电性能提高,居里温度向低温方向移动。借助居里外斯公式证明了所有陶瓷组分均为典型的弛豫型铁电体。

Lead-free piezoelectric ceramic SrxBa1-xNb206 （SBN, x = 0.49-0.56） were prepared by the conventional solid state method with SrCO3, BaCO3 and Nb2O5 as raw materials. The effects of the composition and sintering temperature of the SBN ceramic on its phase structure, micromorphology and dielectric properties were studied. The results show that all the SBN ceramic samples obtained by sintering the ceramic powders at 1380℃ are single phase ceramic with tungsten bronze structure. As the x value increases, the densification rate of the SBN ceramic decreases, the grain size towards uniform and the dielectric properties improve, which is strongly conforming to the reduction in the Curie temperature of the SBN ceramic. With the help of the modified uric-Weiss law, all the samples are proved to be typical relaxor ferroelectrics.