锶锆共掺杂对钛酸钡陶瓷结构和介电性质的影响

Effect of Sr and Zr co-doping on structural and dielectric properties of BaTiO_3 ceramics

采用固相反应法制备了(Ba0.85Sr0.15)(Ti1-xZrx)O3(x=0.10,0.15,0.20,0.25)陶瓷.通过X射线粉末衍射、介电温谱测试和电子顺磁共振技术对其进行了结构表征、介电性能评价和杂质定性检测.结果表明:(Ba0.85Sr0.15)(Ti1-xZrx)O3陶瓷显示平均立方钙钛矿结构,随着Zr掺杂量的增加,晶格常数和单胞体积线性增加;介电居里峰以-5.6℃的速率向低温线性移动,(Ba0.85Sr0.15)(Ti0.8Zr0.2)O3陶瓷的介电峰值超过8 000,并发生在室温附近,扩散系数γ=1.90,材料实现Y5V介电指标;除Sr/Zr双位替代效应导致介电峰更加扩散外,Fe和Mn杂质在Ti位的存在也是实现Y5V介电指标的主要原因之一.

（Ba0.85Sr0.15）（Ti1-xZrx）O3（x=0.10,0.15,0.20,0.25） ceramics were prepared by solid state reaction method.The structure,dielectric properties,and impurities were characterized by X-ray diffraction（XRD）,dielectric-temperature measurements and electron paramagnetic resonance（EPR）.（Ba0.85Sr0.15）（Ti1-xZrx）O3 ceramics show a average cubic perovskite structure.With the increase of Zr dopant,crystal constant and unit cell volume increase linearly,and the dielectric Curie peak moves toward low temperature at a rate of-5.6℃.The dielectric constant maximum of（Ba0.85Sr0.15）（Ti0.8Zr0.2）O3 ceramic exceeds 8 000 in the vicinity of room temperature,with a diffusivity parameter γ=1.90,meeting dielectric specification Y5V.The displacement of Sr and Zr at Ba and Ti-sites makes dielectric peak more diffused.In addition,the existence of Fe and Mn impurities at Ti sites is one of the main reasons to realize Y5V.