【摘要】 用改进的sol-gel工艺制备了细晶钛酸锶钡(Ba0.6Sr0.4TiO3,BST)陶瓷块体,研究了BST陶瓷的结晶与介电性能。在这种改进sol-gel的工艺中,用传统的固相反应煅烧形成BST粉体,经高能球磨制备BST纳米陶瓷粉体,再将一定质量的纳米粉体加入到相同化学组成的BST的溶胶液中,经普球球磨12h后,制备成悬浮性好,分散均匀的浆料。浆料可用来制备BST陶瓷,并在1200℃保温2h烧结成瓷,结果显示,BST陶瓷块体结构致密,晶粒尺寸在0.15~2μm之间。分析了样品的介电性能和晶粒尺寸对材料介电性能的影响。介电温谱显示,在0℃,100kHz时,相对介电常数为2500,介电损耗为0.02;并且存在明显的弥散相变。更多还原

【Abstract】 Barium strontium titanate(Ba_0.6Sr_0.4TiO₃,BST) ceramic bulk materials are fabricated by using a modified sol-gel method.In this novel route,the calcined BST ceramic powder was prepared by conventional solid state reaction,the nano sized powder was produced by high energy planetary ball mill machine.A amount of nano sized BST powders were uniformly dispersed into BST sol solution with the same chemical composition as the powder. The uniform suspension slurry was obtained by conventional ball milling for 12h.The BST ceramic green bulks were obtained by this slurry.The result shows that the dense fine-grained ceramics were prepared with the grain size with 0.15～2μm at 1200℃ for 2h.In addition,the electrical properties of BST bulks were investigated,and the grain size effect on the dielectric properties were discussed,respectively.The temperature dependence of dielectric constant and dielectric loss of BST bulk materials exhibits apparent characteristics of diffused phase transition,dielectric constant is 2500,dielectric loss is 0.02,respectively at 0℃,100kHz.更多还原