B2O_(3)⁃Bi_(2)O_(3)⁃ZnO⁃Al_(2)O_(3)玻璃助烧剂对BaTiO_(3)陶瓷烧结条件、晶体结构和介电性能的影响

Effect of B2O_(3)⁃Bi_(2)O_(3)⁃ZnO⁃Al_(2)O_(3) glass additive on sintering condition,crystal structure,and dielectric properties of BaTiO_(3) ceramics

通过调节B2O_(3)-Bi_(2)O_(3)-ZnO-Al_(2)O_(3)(BBZA)玻璃的添加量研究其对钛酸钡(BaTiO_(3))陶瓷烧结条件、晶体结构和介电性能的影响。结果表明:添加适量的BBZA玻璃能够有效地将BaTiO_(3)陶瓷烧结温度由1350℃降至950℃,并使其致密化。同时,添加BBZA玻璃后,BaTiO_(3)的晶体结构随着烧结温度的升高而发生转变(立方相→四方相)。另外,BBZA玻璃的引入使BaTiO_(3)陶瓷的居里峰得到了有效的抑制和拓宽。陶瓷微观形貌显示,玻璃相均匀分布在BaTiO_(3)晶粒表面。优化的BaTiO_(3)陶瓷制备条件如下:BBZA添加量(质量分数)为2.0%,烧结温度为950℃。在该条件下制备的BaTiO_(3)陶瓷介电常数达到1364,介电损耗低至1.2%。

The effects of B2O_(3)-Bi_(2)O_(3)-ZnO-Al_(2)O_(3)(BBZA)glass on the sintering conditions,crystal structure,and dielectric properties of barium titanate(BaTiO_(3))ceramics were investigated.The results show that the addition of the appropriate amount of BBZA glass powder can effectively reduce the sintering temperature of BaTiO_(3) ceramics from 1350 to 950℃and make it densified.Consequently,the structure of BaTiO_(3) phase changed(cubic phase→tetragonal phase)with the increase of sintering temperature after adding BBZA glass.Additionally,the Curie peak of BaTiO_(3) ceramics were effectively suppressed and broadened.The ceramic microstructure showed that the glass phase was uniformly distributed on the surface of BaTiO_(3) grains.The optimized preparing conditions for the BaTiO_(3) ceramics were as follows:the addition(mass fraction)of BBZA glass was 2.0%and the sintering temperature was 950℃.The BaTiO_(3) ceramics prepared under these conditions had a dielectric constant of 1364 and a dielectric loss as low as 1.2%.When the sintering temperature was higher than 950℃,the addition amount of BBZA glass should not be greater than 2.0%,too much BBZA glass will lead to the semiconducting of BaTiO_(3).