研究了氟化锂助烧剂对钛酸锶钡(Ba0.6Sr0.4Ti O3,BSTO)陶瓷晶体结构、微观形貌和介电性能的影响。XRD图谱显示,添加氟化锂助烧剂时,钛酸锶钡晶体结构未发生明显变化。样品SEM照片显示添加氟化锂可以增加钛酸锶钡陶瓷晶粒尺寸,显著降低材料介电损耗,提高材料综合介电性能。添加5%(质量分数)氟化锂的钛酸锶钡陶瓷介电常数为3360,介电损耗可降至3.5×10-4,介电可调性为44%(150 k Hz,1.6 k V·mm-1)。
Lithium fluoride was employed as sintering aids to adjust the microstructure and dielectric properties of barium strontium titanate ceramics(Ba0.6Sr0.4Ti O3, BSTO). The phase structure, microstructure and dielectric properties of Li F doped BSTO ceramics were studied. The XRD patterns show all samples exhibit a perovskite structure, and no secondary phased is observed. The SEM photographs indicate that the grain size is increased with the increasing of Li F additives. The dielectric constant is reduced with a small amount of Li F and increased with further increase of Li F additives, while the dielectric loss is declined significantly with a small amount of Li F. The dielectric properties are influenced strongly by Li F additives, but the Curie temperature of the samples remains the same. The K-factor is increased with the increasing of Li F additives. BSTO ceramics with 5 wt% Li F additives possess the highest performance. The room temperature dielectric constant, dielectric loss, and relative dielectric tunability at 150 k Hz are 3360, 3.5×10-4, and 44%, respectively.