指纹的法医鉴定被广泛用于犯罪的人身认定,已成为基础的法庭证据。随着稀土荧光粉的快速发展,使检验和鉴定潜在指纹成为了可能。采用高温固相法合成了用于显现潜在指纹的Ba2-xSi O4:Eu2+x荧光粉,测量了在1300℃下保温3 h时样品的激发和发射光谱,研究了不同Ba2+和Eu2+浓度荧光粉的荧光光谱性质。用X射线衍射分析荧光粉在不同浓度的物相,确定还原气氛中Ba2-xSi O4:Eu2+x荧光粉的最佳合成浓度为x=0.08,可得到较好发光性能的硅酸盐荧光粉。重点讨论了对荧光粉粒径大小的优化、粉体的无机后处理和粉体表面有机修饰等性能优化,使其能用于显现清晰的潜在指纹。
Fingerprint in forensic identification is widely used for confirming criminals, as the basis of forensic evi- dence. With the development of rare-earth phosphors, it is possible to detect and identify potential fingerprints. By using high-temperature solid state reaction method in a reducing atmosphere, Ba2_xSiO4 :Eu2x+ phosphors used for latent fingerprints were synthesized. The photoluminescence excitation and emission spectra of the samples synthe- sized at 1300℃ for 3 h with different concentrations of Ba and Eu2+ were measured and studied. X-ray diffraction was used to analyze the structure phase of phosphors with different concentrations of Eu2+ . The results suggest that the optimum x is 0.08 in Ba2_xS1O4 :Eu2+x phosphors for the silicate phosphor Ba1.2aSiO4:Eu2+/0.8 having the strongest luminescent intensity. The effects and optimization of particle size, inorganic dealing, and surface organic modifica- tion of the phosphors were discussed in detail, which could make the phosphors applicable for displaying clear po- tential fingerprints.