Ceria (CeO₂) nanocrystals dispersed in silica were prepared by sol-gel, a very suitable method for large-scale production. The formation of cubic fluorite structure of CeO₂ nanocrystals was confirmed by XRD, TG-DTA and TEM. The average nanocrystalline size has been calculated ~3-5 nm using Debye-Scherrer formula for different annealed samples. The calculated nanocrystalline sizes were compared with W-H plot and TEM histograms. Different structural parameters like microstrain, lattice constant, dislocation density, X-ray density and activation energy were also calculated for all prepared samples. We have examined the photoluminescence (PL) due to defect centers and Ce³⁺ ions present in prepared nanopowder which were excited at two different wavelengths. PL study revealed the effect of annealing on the emission spectra and resulted that the emission efficiency of direct excitation at λ_ex = 325 nm was enhanced with respect to the indirect λ_ex = 250 nm. The emission produced from CeO₂ nanocrystals dispersed in amorphous silica matrix has been influenced by many factors such as the modification of the ligand field around the Ce³⁺ ions in silica, presence of hydroxyl ions and annealing temperature also. Detailed Energy transfer mechanism has been explained with all possible transition lines.

通过溶胶-凝胶制备分散在二氧化硅中的二氧化铈（CeO ₂）纳米晶体，这是非常适合大规模生产的方法。XRD，TG-DTA和TEM证实了CeO ₂纳米晶立方萤石结构的形成。对于不同的退火样品，已使用Debye-Scherrer公式计算了约3-5 nm的平均纳米晶体尺寸。将计算出的纳米晶体尺寸与WH图和TEM直方图进行比较。还为所有制备的样品计算了不同的结构参数，如微应变，晶格常数，位错密度，X射线密度和活化能。我们已经检查了由于缺陷中心和Ce ³⁺引起的光致发光（PL）制备的纳米粉中存在的离子在两个不同的波长被激发。PL研究揭示了退火对发射光谱的影响，结果表明 ，相对于间接_λex  = 250 nm ，直接激发在_λex = 325 nm处的发射效率更高。由分散在无定形二氧化硅基质中的CeO ₂纳米晶体产生的发射受到许多因素的影响，例如二氧化硅中Ce ³⁺离子周围的配体场的改变，羟基离子的存在以及退火温度。已经用所有可能的过渡线解释了详细的能量传递机制。