低温固相反应法制备铈酸镧粉体及其烧结性能研究

以六水合硝酸镧和六水合硝酸铈为原料，一水合柠檬酸为络合剂，通过低温固相反应法制备铈酸镧前驱体，经不同温度煅烧制备铈酸镧粉体。利用红外光谱和综合热分析研究前驱体的结构和热分解过程，并通过X射线衍射分析、扫描电子显微镜观察、透射电子显微镜分析和体积密度测试等手段对不同煅烧温度合成的粉体物相、形貌及烧结性能进行表征。结果表明:当煅烧温度达到600 ℃时，前驱体开始生成铈酸镧晶体，且随着煅烧温度的提高，晶体发育不断完善，晶粒逐渐长大。经800 ℃煅烧可获得单相的铈酸镧粉体，再经1600 ℃烧结，试样的相对密度达到95.5%。

Preparation and sintering properties of lanthanum cerium powders by low temperature solid state reaction

La₂Ce₂O₇ precursors were synthesized by the low temperature solid state reaction,using lanthanum nitrate hexahydrate,cerium nitrate hexahydrate,and complexant citric acid as the raw materials.La₂Ce₂O₇ powders were prepared by calcining the precursors at different temperatures.The structure and thermal decomposition process of the La₂Ce₂O₇ precursors were studied by the infrared spectroscopy and comprehensive thermal analysis.The phase composition,microsreucture,and sintering properties of the La₂Ce₂O₇ powders calcined at different temperatures were characterized by X-ray diffractometer(XRD),scanning electron microscope(SEM),transmission electron microscope(TEM),and density test.The results show that the,the lanthanum cerium grains are formed when the calcination temperature is 600℃.With the increase of the calcination temperature,the crystal continuously develops and the grains gradually grow up.The single phase La₂Ce₂O₇ powders can be obtained at the calcining temperature of 800℃,and the relative density of La₂Ce₂O₇ samples sintered at 1600℃can reach 95.5%.