自蔓延低温燃烧-溶胶凝胶合成Ce_(0.8)Sm_(0.2)O_(1.9)及烧结性能

Preparation and sinterability of Ce_(0.8)Sm_(0.2)O_(1.9) powders by sol-gel and low temperature self-propagating synthesis

用甘氨酸作还原剂、硝酸盐作氧化剂,采用溶胶-凝胶与自蔓延低温燃烧相结合的方法制备了超细Ce0.8Sm0.2O1.9(SDC)固溶体,对所合成的粉体分别采用XRD、SEM和BET法进行了表征。结果表明,600℃焙烧产物是具有较高相纯度的单一立方相萤石型结构固溶体,根据XRD估算晶粒度为13～30nm。甘氨酸与金属硝酸盐(G/N)摩尔比对粉体的微观形貌和烧结性能有很大影响,当G/N摩尔比为2和3时,形成具有松散结构的粉体,该粉体具有很好的成型和烧结性能,将素坯在1400℃保温2h,得到的陶瓷烧结体平均晶粒尺寸为0.5μm,相对密度达到95%以上。

Ultrafine Ce0.8Sm0.2O1.9 （SDC） solid solution powders were prepared by the combination of sol-gel process and self-propagating low temperature combustion synthesis with glycine as reductant and metal nitrates as oxidant.The phase identification,morphology and specific surface area of SDC powders were investigated by XRD,SEM and BET method,respectively.The results showed that SDC powders calcined at 600℃ with crystallites in the 13—30 nm ranges had a pure cubic fluorite crystalline structure.It was found that the molar ratio of glycine to metal nitrate had a great effect on both the morphology and sinterability of the powders.When the molar ratio of glycine to metal nitrate was 2 and 3,the SDC powders possessed a loose structure.The powders had good sinterability in the experiment and the sintered specimens with relative density up to over 95% could be prepared by sintering at 1400℃ for 2 h.The average grain size of the sintered specimens was 0.5 μm.