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%.