pH值对共沉淀法制备ZnNb_2O_6粉体性能的影响

Influence of pH Value on the ZnNb_2O_6 Phosphate Powders by Precipitation Method

以Zn(NO3)2溶液和Nb2O5凝胶为原料,氨水为沉淀剂,采用化学共沉淀法成功合成ZnNb2O6微波介质陶瓷粉体。利用差热分析(DTA)研究了共沉淀前驱体的分解过程,利用XRD跟踪粉体的相演变,TEM对粉体的形貌进行观察,研究了反应pH、煅烧温度对ZnNb2O6粉体物相、粒度的影响。研究发现,煅烧温度在800℃时可合成物相单一的ZnNb2O6,随着溶液pH值的增大,合成的ZnNb2O6粉体晶粒尺寸明显减小。在pH=10,800℃时可合成棒状的,平均粒径尺寸约为100nm的ZnNb2O6粉体。

ZnNb2O6 ceramic powders was successfully synthesized by precipitation method with Nb2O5 and Zn（NO3）2·6H2O as raw materials and using aqueous ammonia as precipitating agent.The decomposition of precursors were investigated by differential thermal analysis（DTA）.The phase contents were studied by the powder Xray diffraction（XRD）.Particle size and morphology were studied by transmission electron spectroscopy（TEM）.The research showed that single phase ZnNb2O6 powders could be obtained at 800 ℃,the powder grain size decreased when the pH value increased.As pH=10,the average grain sizes with diameter of 100 nm could be obtained for ZnNb2O6 ceramics powders at 800 ℃.