钙热还原法制备LaB_(6)纳米粉体及其表征

Preparation and Characterization of LaB_(6)Nanopowders by Calciothermic Reduction

首次采用钙热还原法成功制备了LaB_(6)纳米粉体,通过X射线衍射仪(XRD)和场发射扫描电镜(FE-SEM)研究了反应温度对粉体产物物相结构、形貌和粒度的影响,并采用紫外/可见/近红外分光光度计(UV-VIS-NIR)对纳米粉体光吸收性能进行表征。结果表明:在反应温度800℃下制备的LaB_(6)纳米粉体为简单立方单相结构,结晶性良好,颗粒呈类球形形貌,平均晶粒尺寸为(35±6)nm。随着反应温度的升高,粉体颗粒尺寸增大,向立方形貌转变。吸收光谱表明800℃下所制备LaB_(6)纳米粉体在紫外区和近红外区有很强的吸收特性,最大透射光波长为595nm,与LaB_(6)的第一性原理计算结果较一致。

LaB_(6) nanopowders were successfully prepared by calciothermic reduction method for the first time.The effects of reduction temperature on the phase composition,morphology and particle size of powder products were studied by X-ray diffractometer(XRD)and field emission scanning electron microscope(FE-SEM),and the optical absorption properties of nanopowders were characterized by UV/VIS/NIR spectrophotometer.The results show that the prepared LaB_(6) nanopowders have a simple cubic single-phase crystal structure,good crystallinity and nearly spherical particle morphology with an average grain size of(35±6)nm.With the increase of reaction temperature,the particle size of the powders increases and the particle morphology shifts to cubic shape.The absorption spectrum shows that the LaB_(6) nanopowder prepared at 800℃has strong absorption properties in the ultraviolet and near-infrared regions,and its maximum transmission light wavelength is 595 nm,which is essentially in agreement with the first-principles calculation results of LaBe_(6).