Sol-Gel法制备硼酸钐粉体及光反射性能研究

Light-reflective properties of samarium borate powders prepared by sol-gel method

以柠檬酸为络合剂,采用溶胶-凝胶法制备前驱体,在高温煅烧后得到白色的Sm BO3粉体。利用TG-DSC、XRD、SEM等对反应过程和机理进行分析研究。结果表明：在800℃煅烧后得到粒度尺寸为100~200 nm的颗粒状三斜相Sm BO3,在1 100℃出现由三斜相到六方相的转变,在1 300℃得到晶型完整的短棒状六方晶相Sm BO3;三斜相的Sm BO3在800~1 200 nm波段内出现窄吸收峰,漫反射率在1 073 nm处最低达到35.8%,具有良好选择性吸收效果;六方相Sm BO3吸收峰出现红移,在1 079 nm处最低为56.8%,吸收效果不如三斜相Sm BO3;三斜相的Sm BO3对波长在1 073 nm附近的激光具有较好的选择性吸收效果。

Sm BO3 powders were prepared by calcination of precursor,which was obtained by sol-gel method using citric acid as complexing agent. TG-DSC,XRD,SEM and other measurements were used to analyze the procedure and mechanism of the reaction. The results show that particle size distribution of triclinic phase Sm BO3 ranges from 100 nm to 200 nm after calcining at800 ℃. Then the transition from triclinic phase to hexagonal phase occurs at 1 100 ℃. At last,the short stick hexagonal type Sm BO3 is obtained at 1 300 ℃. The triclinic phase Sm BO3 has a narrow-gap absorption from 800 nm to 1 200 nm,whose diffuse reflectivity reaches 35.8% at 1 073 nm. However,the absorption of hexagonal phase Sm BO3 has red shift to 1 079 nm and the reflectivity efficiency is 56.8 % and the absorption effect is less than triclinic phase Sm BO3. The spectrum shows that the triclinic type Sm BO3 has good selective absorption for laser whose wavelength near 1 073 nm.