论文部分内容阅读
The nano-Y_2O_3 was prepared from YCl_3 by the citrate precipitation method. The precursor powders were prepared by 0.1 mol/L YCl_3 solution and 0.1 mol/L hydrochloric acid in the presence of 1% surfactant PEG2000, which was dried via an ethanol azeotropic distillation method. The effects of reaction temperature, precursor concentration, hydrochloric acid concentration, surfactant, and calcination temperature on the mean sizes of nano-Y_2O_3 were studied. It was found that the highest yield of precursor was about 70% at the p H value of 5.0, and the yield decreased rapidly at the p H value below 4 or over 6. The reaction temperature revealed no effect on the size of precursor. The optimized precursor concentration and hydrochloric acid concentration were both 0.1 mol/L. Several typical analytic techniques such as particle size analyzer, X-ray diffraction(XRD), thermogravimetric and differential thermal analyses(TG-DTA) and scanning electron microscopy(SEM) were used to determine the characteristics of the prepared nano powders. Homogeneous torispherical nano-Y_2O_3 with the smallest size(20 nm) could be obtained by calcining the precursor powders at 800 oC for an hour.
The nano-Y 2 O 3 was prepared from YCl 3 by the citrate precipitation method. The precursor powders were prepared by 0.1 mol / L YCl 3 solution and 0.1 mol / L hydrochloric acid in the presence of 1% surfactant PEG 2000, which was dried via an ethanol azeotropic distillation method. The effects of reaction temperature, precursor concentration, hydrochloric acid concentration, surfactant, and calcination temperature on the mean sizes of nano-Y_2O_3 were studied. It was found that the highest yield of precursor was about 70% at the p H value of 5.0, and the yield decreased rapidly at the p H value below 4 or over 6. The reaction temperature revealed no effect on the size of precursor. The optimized precursor concentration and hydrochloric acid concentration were both 0.1 mol / L. Several typical analytic techniques such as particle size analyzer, X-ray diffraction (XRD), thermogravimetric and differential thermal analyzes (TG-DTA) and scanning electron microscopy (SEM) were used to determine the ch Homogeneous torispherical nano-Y_2O_3 with the smallest size (20 nm) could be obtained by calcining the precursor powders at 800 oC for an hour.