超细银包覆BaTiO3粉体的制备

讨论了金属-陶瓷复合材料超细银包覆BaTiO3粉体的制备条件，采用扫描电镜，激光粒度分布仪，比表面积分析仪及X射线荧光光谱仪表征了复合粉末颗粒的形貌和粉体的团聚状态。讨论了银在钛酸钡粉末表面的包覆形式。采用化学镀的方法在BaTiO3表面沉积金属银。在天然高分子表面活性剂的保护下，Ag(NH3)2^ 被水合肼还原得到分散性良好的不同含银量的复合粉体。最佳的反应条件是：银含量0．1％～0．5％，Sodium Alginate／Ag(质量比)20％，粉末中Ag含量小于80％，反应时间120min，水合肼浓度0．8％。实验表明所得颗粒是银包覆在BaTiO3表面的形成一定银层厚度的复合体系。

Preparation of Ultrafine Silver Coated BaTiO3 Powder

The preparation of metal-ceramic composite material, silver coated BaTiO3 powder, was investigated. The shape of single particle and congeries state were studied with SEM and laser particle size analysis. The existing state of silver on BaTiO3 was also discussed. Silver was deposited on BaTiO3 with chemical deposition method. Protected by surfactant, Ag(NH3)2 was reduced by hydrazine + hydrate, and the composite powder with excellent dispersibility was obtained. The optimal conditions are: concentration of silver 0.1%~ 0.5%, surfactant/ Ag(W/W)20%, the ratio of silver of composite powder < 80%, reaction time 120min and the concentration of hydrazine hydrate 0.8%. The particle size in SEM spectra and EDX analysis suggests that the particle is the composite material with silver coated BaTiO3.