关键词: 关键词：六硼化钙；纳米粉末；高分辨透射电镜；吸收光谱

Abstract:

Abstract: Calcium hexaboride (CaB6) nanopowder was prepared by low temperature chemical reaction of CaCl2 and NaBH4. X

ray powder diffraction pattern indicated the formation of CaB6 crystal, the field emission scanning electron microscope (FESEM)

image showed that CaB6 nanopowder was agglomerated with cubic crystals with grain size of ～80?nm. HRTEM photographs indicated

that the nanoparticles were singlecrystal corresponding to the FESEM and XRD results, and the CaB6 crystal consisted well

crystallized CaB6 core and thin amorphous shell (4～5?nm). Fourier transform Infrared (FTIR) and UltravioletVisibleNear

Infrared (UVVISNIS) spectra were investigated to characterize optical properties of CaB6 nanopowder, compared with

micrometer CaB6 powders. Compared with the weak absorption bands of micronpowder, obvious Einstein shift and band broadening

occurred in nanopowder spectrum, which was thought to be related to lattice expansion and nanometer effect. UVVISNIS

spectrum showed that CaB6 nanopowder could absorb ultraviolet rays and the absorption peaks exist blue shift of spectrum,

compared with micron powder. In conclusion, CaB6 nanopowder showed absorbency within all the detected regions in FTIR and UV

VISNIS spectra, especially to the infrared.

Key words: Key words: CaB6; nanopowder; HRTEM; absorption spectra