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分别采用碳酸铵((NH4)2CO3,AC)和碳酸氢铵(NH4HCO3,AHC)作沉淀剂制备胶质溶液,利用胶质溶液喷雾热解制备纳米晶氧化钐掺杂氧化铈(Sm0.2Ce0.8O1.9,SDC)电解质粉末。通过X射线衍射、热重分析和扫描电镜表征粉末和陶瓷的结构和形貌,探讨沉淀剂对前驱体和SDC粉末形貌、粒径和结晶相的影响及作用机理。结果表明:通过AC途径制备的喷雾热解粉末呈球状,经700℃热处理后,得到的SDC粉末聚集体粒径小于0.5μm,具有很高的烧结活性,经1250℃烧结4h获得的陶瓷密度达到理论密度的96%;通过AHC途径制备的喷雾热解粉末经热处理后仍保持片状,相应的陶瓷呈多孔结构,只有理论密度的79%。
The colloidal solution was prepared by using ammonium carbonate ((NH4) 2CO3, AC) and ammonium bicarbonate (NH4HCO3, AHC) as precipitants. Spherical nanocrystalline samarium oxide doped cerium oxide (Sm0.2Ce0. 8O1.9, SDC) electrolyte powder. The structure and morphology of the powders and ceramics were characterized by X-ray diffraction, thermogravimetric analysis and scanning electron microscopy. The effects of precipitants on the morphology, particle size and crystalline phase of the precursors and SDC powders were investigated. The results showed that the spray pyrolysis powder prepared by AC route was spherical. After heat treatment at 700 ℃, the particle size of the aggregates of SDC powder was less than 0.5 μm and had high sintering activity. The density of the ceramic obtained after sintering at 1250 ℃ for 4 h reached Theoretical density of 96%; spray pyrolysis powder prepared by the AHC way after heat treatment remained sheet, the corresponding ceramic porous structure, only the theoretical density of 79%.