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以硝酸盐做氧化剂,柠檬酸为燃料,采用低温燃烧法制备纳米级超细Ce0.8Y0.2O1.9(YDC)固溶体。利用TG-DSC,XRD,SEM,FT-IR和BET等手段对凝胶前驱体的热分解行为、相转化过程和YDC粉体的性能进行表征。TG-DSC结果表明,柠檬酸-硝酸盐干凝胶的点火温度约为263.3℃;经XRD测试,粉体经600℃焙烧即形成了单相立方萤石型结构的固溶体,晶粒度为16～23 nm。柠檬酸与硝酸盐摩尔比(CA/N)对粉体的微观形貌、比表面积和烧结活性有显著影响。当CA/N为1.5∶1时,粉体粒子间仅有微弱的软团聚,将素坯在1400℃烧结2 h,得到相对密度为95.6%,平均粒径约为0.7μm的陶瓷烧结体。
Using nitrate as oxidant and citric acid as fuel, nanocrystalline ultrafine Ce0.8Y0.2O1.9 (YDC) solid solution was prepared by low temperature combustion method. The thermal decomposition behavior, phase transformation process and YDC powder properties of the gel precursors were characterized by TG-DSC, XRD, SEM, FT-IR and BET. The results of TG-DSC showed that the ignition temperature of citric acid-nitrate xerogel was about 263.3 ℃. After XRD measurement, the powder was calcined at 600 ℃ to form a single-phase cubic fluorite solid solution with a grain size of 16 ~ 23 nm. The molar ratio of citric acid to nitrate (CA / N) had a significant effect on the morphology, specific surface area and sintering activity of the powders. When CA / N is 1.5:1, there is only a weak soft agglomeration between the powder particles, and the green body is sintered at 1400 ℃ for 2 h to obtain a ceramic sintered body with a relative density of 95.6% and an average particle diameter of about 0.7μm.