直接沉淀法制备纳米钛酸钡粉体的表征与介电性能

文中采用直接沉淀法以四氯化钛和氯化钡溶液为钛源和钡源,并以NaOH溶液为沉淀剂一步合成了纳米BaTiO₃粉体,并对所得粉体的形貌、颗粒尺寸及分布、杂质含量、Ba与Ti摩尔比和介电特性进行了分析与测试。实验结果表明:所得BaTiO₃粉体的形貌为球形,具有立方相晶体结构,其平均颗粒尺寸约为60nm,并且颗粒尺寸分布均匀;粉体的Ba与Ti摩尔比为(1.000±0.005),杂质含量小于电子工业行业标准;粉体经过干压成型后在1250℃烧结,所得钛酸钡陶瓷的相对密度达到95%,晶粒尺寸约为1.2 μm ,室温介电常数达到2836。

Characterization and dielectric properties of nano-sized BaTiO3 powders prepared by direct-reactive precipatation

Nanostructured BaTiO₃ powder was prepared by direct reactive precipitation from hydrolyzed TiCl₄ and hydrated BaCl₂·2H₂O, in which NaOH acted as precipitant. The results of TEM and BET analysis show that BaTiO3 powders are near spherical shape with narrow size distribution and the mean particle size is about 60nm. XRD investigation confirmed that the powders of BaTiO₃ had the crystalline of the pseudo cubic structure. FTIR study showed that the powder contained some —OH defects. The Ba/Ti mol ratio was(1.000±0.005) confirmed by chemical analysis.The content of impurity was below the industry standard.The powder could be sintered to a relative density of 95% when sintered at 1250℃ with a grain size of 1.2um.Dielectric constant was near 3000 at room temperature.