沉淀剂对胶质溶液喷雾热解Sm_(0.2)Ce_(0.8)O_(1.9)固体电解质结构的影响(英文)

INFLUENCE OF PRECIPITANTS ON STRUCTURE OF COLLOIDAL SOLUTION SPRAY PYROLYSIS DERIVED Sm_(0.2)Ce_(0.8)O_(1.9) SOLID ELECTROLYTE

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%。

Nanocrystalline samaria-doped ceria（Sm0.2Ce0.8O1.9,SDC） electrolyte powders were prepared by the colloidal solution spray pyrolysis.Ammonium carbonate（（NH4） 2CO3,AC） and ammonium hydrogen carbonate（NH4HCO3,AHC） were used as pre-cipitants,respectively,to prepare colloidal solutions.The X-ray diffraction,thermogravimetry and scanning electron microscope were used to characterize the structure and morphology of the powders and the prepared SDC ceramics.The effects and mechanism of the precipitants on morphology,particle size and crystalline phase of the precursor and SDC powders were discussed.The results show that the as-spray pyrolyzed powders which resulted from the AC method present spherical shape.The SDC powders agglomerates are less than 0.5μm in size after heat-treatment at 700℃,showing high sinterability.96%of theoretical density is obtained when powders are sintered at 1 250℃for 4 h.The as-spray pyrolyzed powders obtained by the AHC method remaine flaky morphology after heat-treatment,and the corresponding ceramics exhibit porous structure with 79%of the theoretical density.